Hacker News new | past | comments | ask | show | jobs | submit login
I booked my cheapest one-month trip (benbernardblog.com)
239 points by fagnerbrack on April 29, 2021 | hide | past | favorite | 156 comments

Ha, that reminds me of the time when we found a loophole in the European train ticket price system: Deutsche Bahn had (and still has I think) a "Europe Special" where you could buy a ticket from any town in Germany to any town in Europe for 39 EUR flat. Our idea was to travel through Croatia for a few weeks, and we wanted to book a train ticket to Zagreb, from where we would start our trip. Sure enough, bahn.de (the journey planer of Deutsche Bahn) offered us a ticket for a train ride of around 16 hours from our home town to Zagreb, through Austria and Slovenia. We would have had to change trains 2 times.

Then things escalated.

We discovered that we could book the same trip, for the same price, but with a different route, making a 500 km detour inside Germany over my parent's town. Then we discovered that bahn.de allowed us to specify a minimum time to change trains. We set it to 24 hours at my parent's town, letting us stay at my parents for a night. Then we found out that we could set an additional via option in such a way that we had to change trains in Ljubljana. We set the minimum time to change trains there to 24 hours. Then we found out that the ticket price was the same if we travelled not only to Zagreb, but to Split (at the coast), which required a change of trains in Zagreb. But we wanted to stay a few days in Zagreb, and the maximum minimum time to change trains on bahn.de was 24 hours. We then discovered that (at least 5 years ago) all foreign tickets were valid for 30 days in Croatia. Effectively, this meant that we could stay in Zagreb for 30 days, and our ticket to Split was still valid.

We got the ticket. After a week of visiting my parents (1 night stay), Ljubljana (1 night stay), and Zagreb (5 nights stay), we arrived in Split without problems. It was a 1,500 km, 7 day train trip for 39 EUR.

The only minor problem we had was the German conductor in the first train after we visited my parents. He just stared at the monstrous ticket in disbelief and had to finally conclude that it was valid.

After 10 days at the Dalmatian coast, we took the bus home.

Will check it out. Until last year, you could use a neighbor country to buy train tickets to and from Germany. Since you did not have to start using the ticket in the first station but can basically board the train wherever you feel on the booked trip, you were able to buy all bullet train tickets for about 20 Euros (e.g. Berlin>Hannover, Leipzig>Cologne etc.). Best thing: Not bound to a specific train on that day and they were reimbursable until 24h before your trip started. Good times. But all good times come to an end :-(

Just for a comparison: These 20 Euro rides would set you back 150 Euros otherwise.

And for train ride information, there is always: https://www.seat61.com/

Until just a few years ago international train tickets were valid for two weeks. That was really useful, since as long as you travels towards a destination you could get quite cheap tickets for tours through Germany or Europe with multiple stops.

I can attest to what OP @Iqet has said. I had travelled from Berlin to London very cheap in 2011 (I think under 20 Eur , because the whom I bought it from, secondhand, was sharing the group ticket as well). It was my first trip to Europe when I was a student in UK. And I had fallen sick, hospitalized (insurance took care of it), and I missed my flight back, as I was in hospital. I had no money to book a flight or a proper train ride back to UK. That is when one kind stranger helped find this ticket in a website which was only in German and gave me the ticket printout and instructions to board the train. It was literally a life saver.

That’s really awesome.

But why would the system allow for detours like that? I know multi city is a thing for flights, but would have figured the utility less for trains, but I’m not European so for all I know it’s common to make big not-salesmen-problem paths.

Somewhere a coder with a deadline was happy the system worked.

Dealing with insane scenarios is out of scope for current sprint.

Or management gave imprecise requirements, and coder implemented them in the most customer-friendly way without asking any questions.

It's pretty common in Europe for train journey planners to offer a "Via" option. This is often used to select a specific route if multiple options to go from A to B exist (for example, to get a scenic route).

It's not so much the distance, but which trains you take, how fully booked they normally are, and how much in advance you book. Sometimes a detour is cheaper than the direct route.

If you don't mind sitting in the train a bit longer, one possible trick (of many) with the German system is to book most of your trip using regional (non-long-distance) trains, and only a small bit in an IC or ICE. That way you can usually get across the entire country for 39 EUR (or less with a Bahncard) even if booked a few days in advance. Extensions into neighbouring countries often come for (almost) free.

I worked for a while on dynamic packaging models (user clicks on "flight+hotel", books the flight, and then is presented with a list of hotels at their destination). We used time between booking and date of travel as one of the signals, and saw that there was a pretty clear correlation between planning ahead and being more price conscious. I don't think it was a huge effect but it probably bumped down the target price of our offered hotels by a buck or two.

Unrelated side story about this: we also ran some experiments with bumping higher margin (usually meaning higher price) hotels into the top ranking slots to see how it affected conversion percentages. Normally the top slot has the highest conversion and it decays sharply from there. With these experiments running, for most countries you could see a clear change where the peak would move down to slot 2 or 3 or wherever the "natural" #1 hotel was (score one for our models, I guess). This effect was most pronounced with German travelers, and almost nonexistent for French ones.

This type of thing stops being useful when you travel a lot, the loyalty programs wind up making a lot of things much cheaper then they would be to new customers and easier to find and book.

And regarding flights this didn't try to take advantage of some of the common flight booking tricks which can reduce fares much deeper like stopovers, +/- days, and airline switching which are harder to search.

A lot must be really a lot - like large percentages of the year?

I went through the effort to sign up for all the loyalty programs and I travel some for work (or at least I did) - probably 6-12 weeks a year?

The loyalty programs were mostly negligible in value they provided. Some (like Amex Platinum rewards) were so hostile to get the value from it made me irritated to use it - not a direct hotel loyalty example, but a lot of them felt like this (calculated to give you the least value possible). Airline loyalty sucks and is a pain to use.

The CSV card was probably the only exception to this that I can think of.

About 7 years ago, I got an invite to the highest level of two programs for a year (platinum? vibranium? i don't know.) I used travel about once a month for work, which is not nearly enough to earn those levels.

It was amazing -- lounge access, free upgrades, free limos, free food and drinks, front of the line, expedited service everywhere, endless gifts (who doesn't need more socks?) It was a pretty good year to fly. :-)

Airline loyalty value depends heavily on how frequently you can travel on one carrier and how much you value things like upgrades.

Hotel loyalty is a whole different ballgame because the margins that hotels pay to the booking sites are much higher (20-30%). For a long time hotels were contractually obligated to give the aggregators their lowest publicly available price ("most favored nation" - some recent EU regulation may have cut down on this, not sure what the current status is). One way of getting around that is direct marketing, so hotels are highly incented to get you to sign up for a loyalty program, give you 10% off, and keep the other 10% that would otherwise go to Booking/Expedia.

The key to extracting value from airline loyalty programs is not being the one paying for the flights. Many programs now don’t care as much for the number of flight miles as the dollars spent.

Business travelers are much less price discriminatory and so airlines get fatter margins. They loyalty programs end up transferring value from your firm to you.

Yeah, airline loyalty is (was?) pretty much about focusing on one carrier (and its partners) wherever possible even if it's not always ideal. And flying a lot. I'd hit 60-75K miles a year on one carrier. Who knows if I'll ever do that again.

Hotels were always something I signed up for and used when I could but I never did unnatural acts to do so. May be different especially if traveling domestically primarily to $BIGCHAIN which almost always has an option.

For me I was able to extract value with maybe... 5-6 trips a year minimum. More then that and it just gets easier. But I guess it partly depends on what you're valuing.

For instance... If you travel with no checked bags ever, and you fly on an airline that requires you to pay for checked bags. You won't see the value of having free checked bags when you achieve an airline status. There's lots of little things like this.

Yeah - I think that was the case for me.

I didn't care about checked bags. If I have to jump through a bunch of hoops to get a limited (and expiring) $200 credit it mostly annoys me more than helps.

It's not uncommon for consultants to fly weekly for long term projects.

Maybe a silly question but what’s the CSV card?

Chase Sapphire Reserve


I save more money on my Amex platinum every year than I spend. Not even trying, really. If you use Uber, rent cars, and click the cashback program links in your emails it's actually quite easy to come out ahead.

Hotel stays and checked bag fee waivers will put you way into the green.

They dole out the uber money a tiny bit each month and if you don't use it that month it doesn't roll over (obnoxious).

You don't get the airline credits by default you have to register with one through their shitty website. You also have to choose a specific airline, CSR lets you just use the credits on any travel by default.

I don't like paying $550/yr fee for something where I'm supposed to be the customer and then have every feature feel like something I have to read the fine print for so I don't get screwed.

I ended up just switching to the Apple Card. While the rewards are subpar, at least the software is best in class and they make GS agree to not sell your transactions to third parties.

The best Amex feature was the Delta lounge access (only when flying on Delta) - the Delta lounges are really nice, particularly the one at SFO. The Amex lounges are great too, but there aren't many of them and they're often in terminals that are inconvenient (or United - which I try to avoid at all costs).

I think there's probably an opening here for a startup with a credit card that's actually good.

the uber money is $30/mo. You can use it with Uber Eats. It's more than half of your $550/yr fee. $190 for all of the other benefits that the card provides is INSANELY CHEAP.

Most of the other programs you just sign up once. It's so easy, I don't understand what you're complaining about. If it's difficult for you to use the benefits, you probably aren't the target type of customer for that card.

The merchant discounts and event ticket presales/reserved seating are a massive boon. I get just shy of front row seating at many events because of AmEx. There's usually at least $50 in merchant discounts available each month that I'll use.

It used to be $15/mo and $20 in December.

It should be granted up front for uber use over the year, not spread out each month to try to scam you out of it.

With CSR you get a $300 travel credit that's automatically applied to any flights or car services. When you book travel you can use credits to reduce flight cost with a slider. It's much nicer for the user.

Signing up isn't technically challenging - it's forcing me to do it that bothers me. I don't like Comcast style customer relationships. If you're giving the reward just give it to me, don't make me jump through hoops.

As a travel newbie, any recommendations for loyalty programs or tips + tricks?

Get a travel rewards credit card and read all of the benefits. The chase sapphire reserve is phenomenal to start with.

For the loyalty programs you don't see the value immediately, you need to travel a fair bit before those programs start having much/any return. Initially try to stick with the same couple of brands to maximize the loyalty programs. Try to apply a corporate rate code to any hotels and car rentals, makes a huge difference.

Figure out what airline local to you has the most/best routes that you want to take and stick with it. That may depend on where you want to fly too.. so spend some time figuring that out.

I'm not a hyper-optimizer but pre-pandemic I was traveling a good third of the time.

Basically. Pick an airline and travel with them whenever you can. Enroll in all the hotel loyalty programs but they're mostly not worth over-optimizing around. If you travel a lot, premium credit cards may make sense.

It doesn't matter much until you're travelling what most people would consider a lot. But then it can start to become significant in terms of money and/or comfort.

Checkout /r/awardtravel on reddit

This is what https://www.hopper.com/ does. Didn't quite work out when I tried, prices only kept going up!

Hi there, Hopper engineer here. The blog post is pretty accurate from my experience (lowest prices ~3 months out) but if you apply any of this logic to the past year then you're going to have a bad time. The pandemic caused the entire industry to lower their average flight prices and now that things are starting to return to normal, so are prices. Because of that, predicting price trends based on historic data is a bit tougher.

If you use iOS (not sure if we have it on Android just yet) then I'd recommend looking for something called "auto-buy" when you search for a flight. It's basically a limit order for flights and it'll allow you to set a price that you would be comfortable buying at. If the fare dips to that price then it'll book for you. We've seen some insane deals get booked through this product. Just looking at some of them from yesterday there was a round-trip flight from NFO (Norfolk, Virgina) to MCO (Orlando, Florida) that we originally price quoted at $284 for the user and it was booked at $166.

Why do you have some features on ios but not android? Why isn't this on your website.

Maybe I am old (possible), weird (probable), and out touch (definitely). But I couldn't imagine the case where I am planning on doing research for travel and I would go to an app over a website. For looking at data, typing things in, comparing prices, etc. A phone app really is the worst form factor for that.

I am not sure how big your company is, or how its done. But your product owners are dropping the ball in my opinion. I backed out of the website as soon as I found I couldn't do anything from the website.

I guess I'm also old, weird, and out of touch :) I cannot begin to describe the annoyance I experience with filling in forms on a mobile device, especially if I'm hunting for a good deal `to -> from` and need to keep going back and slightly modifying my search params.

Phones just aren't good at this use-case.

Being (very) cynical, the only reason they're providing a mobile app is because of all the data they harvest (https://www.hopper.com/legal/privacy-policy/).

Thankfully there are millions of people that prefer to use their phone for searching and booking travel and we've been able to build a business around it.

I feel your pain around filling in forms and managing context on mobile devices which is why we've tried to make the process simpler and deliver to customers what's actually important. This article was written by our head of design back in 2018 about why we chose the search parameters we chose for flight search: https://medium.com/life-at-hopper/users-dont-want-filters-th...

He's now leading design at a start-up called Fast trying to apply similar principles to paying for things online.

And who knows how many more untapped because they don't want to use your app?

Every time I've (tried to) use the RyanAir app to book (or browse prices for) a flight, for example, I've given up and used a 'real' computer to go to the website. That's not (just) because the app's bad.

Having app-only features and limited functionality website is just infuriating. Things go wrong with phones, websites are sort of a 'lowest common denominator'; you're not locked out because your phone broke and you had to borrow someone's old one but it's $OS and you're used to $OTHEROS, etc.

> Thankfully there are millions of people that prefer to use their phone for searching and booking travel and we've been able to build a business around it.

How do you know? It's not like you gave them the option. Anyway, like you said, I'm not your demographic and I realise you are helping a lot of people travel more cheaply so I do wish Hopper all the best :)

Yeah, same. Guess the old saying "if something's "free" then you're the product" hits home here too. Forcing the mobile app is a deal breaker.

While that saying applies for things like social media and such, it isn't the case for Hopper because you still have to pay for travel. The app is free, but you still have to pay for any flights or hotels that you book. Usually when an app or online service is free, then you'll see ads serving you content associated with your search behavior because that's the only way that service could monetize itself. Hopper's founder has been pretty adamant that we'll never serve advertisements in the app and we wouldn't be selling user data to 3rd parties and at least in my 4 years at the company that promise has been kept.

I would hand in my resignation if we started serving ads in the app.

This. I also lost interest as soon as I saw the website just re-directed me to an app.

Not sure how much I can say, but it mostly comes down to engineering capacity. We're still a relatively small engineering team (100-200 engineers) and for a long time were more like 30-50 engineers. There's a lot of moving parts in travel and we chose to focus on iOS mainly since it's the has the biggest market share in the US for mobile.

Hundreds of engineers and can’t build a website. Something is wrong here...

It's likely you're underestimating the complexity required to run Hopper and support all existing features. Only a small subset of those engineers will do mobile work. And they likely have many more priorities than building Auto-buy, the benefits and viability of which isn't obvious. So while the rest of the Hopper Eng team churns on with other long- and short-term changes, one or two engineers may have been able to lobby for a POC on iOS. Or maybe it was just a quick week long hackathon project that's still being monitored for ROI.

Something is potentially wrong. Saying "we only have 100-200 engineers, we can't get around to making a website" is a terrible excuse that points to mis-management. It doesn't take more than a couple developers to put together a basic "shopping for flights" web interface. If they have a backend that serves iOS, it should have a REST API, so slapping a web interface on that shouldn't be a big deal.

But it's also possible that it's like someone else mentioned: "if the product is free, then you're the product". Maybe they just don't care to get more customers/solve their problems, because they are harvesting enough data about iOS visitors to make a profit. If they don't want any more customers, then nothing is wrong.

I am young, and decline to comment on the others, but fully agree. It irritates me to try to do such things on my phone; I often give up and reach for a 'real' computer & keyboard to start again and wish I hadn't bothered with the phone to begin with.

If I didn't need a WhatsApp app on a phone in order to use WhatsApp on a computer, I probably wouldn't have a phone, (maybe an emergency use classic Nokia brick) or at least use it extremely infrequently.

Why do you not allow for functionality on your website, but force users to use an app?

They actually tease you by pretending to show results on their website [0] but when you click on any of the flights it just takes you to their homepage.

[0] https://www.hopper.com/deals/best/from/city-toronto-YTO/to/c...

I'm impressed you even found that. AFAIK there's no link to it anywhere from hopper.com. It was a little SEO project that one of the engineers that's been here a while worked on using our internal prediction APIs. Something like it existed in the app at one point, but the engagement we saw with it was pretty miniscule.

Appreciate the kind response. Those pages are linked right on the homepage, I clicked on the Paris[0] one.

[0] https://i.imgur.com/7ey6spH.png

Oh wow, goes to show you what I know... I assume when we were working with the company we contracted out to build that fancy website they asked if we had anything to link to for flight deals that we were just like "this engineer had a little pet project you could link to". The funny thing is a new hire just asked why we didn't have anything in the app for "best deals in general from my city" and I responded by linking to that project.

It used to exist as its own separate app called "Get The Flight Out" but for some reason we removed it from the app store. We also had a feature devoted to something similar for "flexible watching" but it never got much engagement and it didn't warrant the infrastructure cost it required to keep up.

yeah... i find that a bit disgusting.

Assuming good faith, the business decided that mobile apps were more valuable to their customers so they've spent their (inherently limited) resources improving the mobile apps. Assuming bad faith it's because they want to get whatever data they can off of you while using the mobile app. But due to Apple more clearly exposing what permissions an app uses, that is not quite the concern it used to be.

I'd bet anything that the business didn't decide that a mobile app was more valuable to their _customers_. Maybe more valuable to them, but not to their customers.

It is very rare that an app will provide more value than a website. And most of the time when it does, it's just because the website is shit, and they spent more time on the app. But if they focused on the website, it would be way better than whatever experience the app is giving you.

Here's something to think about: would you download and install a desktop application for every random website you come across? No? Then why do it on your phone? People must just make better websites.

I'm assuming good faith here, and you should too until you find out otherwise. It's fine to be skeptical, but it's rarely helpful to be cynical.

Yea it's not like you would ever use your phone for anything that you couldn't just use a website for. Before the pandemic when I was at a bar and needed to get a ride home I would just take out my laptop and find the number for a taxi company to call to pick me up. This is the perfect solution to the problem and a mobile app could never be more useful.

Yeah, the parent comment is unnecessarily cynical. I've worked at multiple travel companies that have independently either built an app or considered it based on user feedback. I'm not the biggest fan of the idea but I've come to peace with the idea that other people interact with their devices differently than I do.

I wasn't saying never use a phone when you can use a website. I was saying why have a dedicated phone app when you can just use the browser app on your phone. Or are you saying you downloaded an app on your phone just to lookup taxi numbers?

I'm saying there are 2 multi-billion dollar companies that only had mobile apps for a long time that the vast majority of people use to book rides to places.

Because there was a vacuum in the mobile travel space when Hopper was trying to find its main value proposition and we tried to fill that vacuum. Millennials (and now Gen Z) tend to be pretty price sensitive and they also tend to be a higher share of the mobile user space so it made sense to apply our "you can watch for flights and get notified when the cheapest flight hits what we think is the lowest price" feature on a platform where sending notifications that users actual on is actually feasible. On web, the options are email or web notifications and neither of those are very actionable in a timely manner.

They did preface the post by saying they’re an engineer. Most likely that wasn’t their decision.

I fully expect that it wasn't their decision, but also presume that they'd have insight into why a decision like that would be made.

Also, it allows me to express my disdain at such a decision and if enough other people did too, said engineer has the ability to go up the flagpole and inform the decision makers that there are many people who are displeased at their decision.

I do have that ability, but I also have the sense to know that HN readers is not who we're building the product for and when you look at the travel industry as a whole the SEO/web advertising game is not one you really want to play. Two of the biggest spenders on Google AdWords are Expedia and Booking.com. They spend our annual marketing budget in every like 10 minutes or something like that. We literally can't compete, especially when you consider that Google is doing their own with Google flights and hotel search which favors themselves.

So the smart thing to do (at least in our opinion) was to not even play the search engine advertising game and focus on building mobile apps that users will come back to after using. We tend to see really high retention rates with users because they like the experience and we don't have to pay for the ad impression every time they feel like searching for travel destinations.

To make more money. Like most "dark" patterns.

Just a thought, perhaps it's something to prevent scraping.

This actually is one of the benefits of being a mobile only product! It makes it a lot harder to scrape the data that we produce (prediction and such). I don't think that's ever been the main reason though, just a side benefit.

Why don't you have a web interface?

Just want to say that Hopper is fantastic. Love the simple app design and I’ve gotten some great deals with it. I’m at least one HN reader who does a lot of travel planning on his phone.

The only time I remember the predictions failing badly was booking a flight for the 2017 full eclipse. Hopper kept advising that prices would fall, and no surprise, they never did. Obviously historic data was little help for a rare social event like an eclipse.

Thanks for your answer! This was maybe 2-3 years ago, way before the pandemic hit. I started watching a flight - probably AMS-SAO - a few months in advance and all I got were alerts for the fares going up every other week. Pulled the plug at some point with the usual [expensive] fare. Maybe I was just unlucky.

Norfolk's airport is ORF.

Some cities have their own (not really official AFAIK) codes that represent "any airport in this city", such as "NYC" meaning LGA, JFK, EWR, and maybe also HPN and/or SWF. I think these are mostly created by app/site developers but I could be wrong.

They're metropolitan area codes (https://en.wikivoyage.org/wiki/Metropolitan_area_airport_cod...). They're not consistently useful across sites because different sites connect to different backends (GDS) that may or may not accept them, but it's nice if you consistently use a site that does. Back when Hipmunk was alive QSF was useful to me because it used Sabre as the GDS and would translate it as {SFO, OAK, SJC}. Other sites would show you an airport in Algeria.

Edit: I should note that you should be careful when using these - at least once I accidentally booked a ticket that left from SFO and returned to SJC.

That's the term, it's been a while since I had to work with this stuff. I don't remember if I ever was able to use the metro codes to look up data from a GDS, but I do remember that I once ended up with a dataset where I had to heuristically disambiguate those codes from proper IATA codes; that sucked.

That would require Norfolk to be big enough for two airports :/ The next closest is Williamsburg/Newport News and then Richmond.

You're right, but it was just a brain fart on my part. It was ORF and I don't think Norfolk has a city IATA code.

A shame that the flight wasn't between NFO and MCO; I would love to book a ticket between Orlando and Tonga for only $166.

Ah you're right. Looking at that slack message again it was ORF. Not sure why I wrote NFO.

I'm guessing you had a pretty strong prior that 'prices go down'?

It got me LAX-JFK for $361 during Xmas holiday... usually it's like $600.

This was basically what Hipmunk did. Gather pricing data and make predictions on when it would be cheapest to buy. It happened to be hidden behind a beautiful interface.

I sorely miss it - other sites may provide similar pricing information, but none even come close to match the lovely loading animation that was the joy of using Hipmunk.

Me2. It was so useful. The chipmunk swaying with the airplane arms. :D

I routinely check several times before making a booking. I kept Hipmunk in my apps and bookmarks for years and never turned out a better deal. I deleted it probably only a few months before they closed up.

The interface was cute but that was ‘bout it for me.

Yeah, you pretty much have to browse every major price site and then the suggested vendor directly. And check them on desktop, mobile, and someone else's mobile just to be sure the deals are the best.

And a VPN!

Our all inclusive stay in Mexico last year was significantly cheaper booking within MX vs USA.

Yeap. Haha. Watch out for cookies too.

Bing flights also did this with a very prominent message like "This flight is more expensive than usual...wait 6 days to buy" message....I wonder if part of that explains why bing flights is shut down now?

Kayak and Google flights do this

The annoying part about booking plane tickets these days is that most flight booking websites have very similar and limited functionality for querying and filtering. Sure, there's Matrix ITA and Google Flights is an upgrade too.

But imagine what people could do if you gave them full fledged access to all flight data. The efficiencies!

A lot of flight prices are calculated upon a search query and only guaranteed for that query (and for a set number of minutes). There generally isn't just some sort of table you can look into and get prices unfortunately.

The company I work at provides these sorts of search interfaces to airlines, but all the pricing data we show has to be estimates based on confirmed prices in the past. If you're directly on an airline website (not Google Flights, Kayak, etc) and see a calendar or something that lets you view 60 days of prices or more at once, there's a good chance that was developed by one of our teams. Unfortunately we can't totally guarantee you those prices, and we'll do things like not render those components if our estimate confidence isn't high enough.

Getting a "real" price for a flight is not a particularly fast API call, and also costs the airlines a small amount of money from the provider (almost no airline directly generates their own prices, generally another company does). Fractions of a penny per call, but that really adds up if you just give free bulk direct access to that to customers.

Is that not all totally bonkers?

People who don't work in travel would be horrified at both acceptable latencies in that space and just how old some of the formats involved are.

One example I used to tell people in interviews: ever tried to book a flight more than a year out? You probably can't, because the date format in a PNR is "APR29". That's the underlying data for basically all flights.

There's a paper somewhere (I think from one of the ITA founders) about how flight search is actually NP-complete. I haven't looked carefully but I think these slides cover a lot of it.


"One interesting result not written up here is that even completely fixing the flights and fares of a ticket, so that the only remaining question is how to partition the fares into priceable units, is NP-complete. This is interesting because only flight and fare information makes its way onto printed tickets, not the grouping of fares into PUs. Therefore the problem of just validating a printed ticket is worst-case NP-complete, though it is rarely difficult in practice."

I think the environment has changed since this was project was executed. I am not familiar with the industry but it now seems like travel companies and airlines have more ad-hoc control of their online prices. Someone please correct me here.

Back then (2012) I used a startup called flightfox to find the best travel deals for me (they have since pivoted to corporate travel management). I assumed they performed analysis similar to this article plus some other magic and it worked really well.

Today, I find more deals through "deal spotting" - a community or algorithm scours for deals and then those deals are shared within a community or on a website.

Not really, at least as far as I know. Historically, prices have been set in a pretty ad-hoc manner by revenue managers at the airlines. I'm pretty sure that's where the "best deals for flights are on Tuesdays" thing comes from. Revenue managers would show up to work on Monday, spend the whole day reviewing the performance of their routes and then on Tuesday morning they would set the new prices for flights based on that analysis. In some cases, they mess up and you would get a really good deal because humans aren't perfect.

What has changed a bit is airlines have invested more into machine learning and trying to apply revenue optimization models to programmatically adjust their prices. You still get those weird deals since there's still some ad-hoc price adjustment and also machine learning models aren't perfect, but the pattern is less predictable.

IIRC Flightfox was originally a market where you posted your desired itinerary and constraints and a price, and some travel points nerd could offer you a convoluted routing would meet those constraints for (this is why I ended up booking Star Alliance flights for years through a Colombian carrier's site). It was really helpful for me to spend ~$40 rather than try to learn the collective wisdom of FlyerTalk forums. I think they later pivoted to some more automated system where they'd try to sell the flights directly - I hadn't realized that they were in corporate travel management now.

CEO of Flightfox here. We still absolutely use both technology and humans (that will always underpin our value prop), but we moved from the previous competitive crowdsourced model to a one-on-one model. The short story is that travel search benefits more from depth rather than breadth (at least at the expert level). With multiple travel hackers working at once, they can only invest $fee/n-hackers worth of time and there is a ton of overlap. With a single hacker, they receive all of the $fee and can dig deeper and deeper to uncover better results. The crowdsourced approach was definitely more interesting to consumers, but the results were inferior, especially on the customer service side. Now, we’re actually transitioning behind the scenes from a one-on-one to a collaborative model, which is bringing us new benefits, but requires more systemization.

Today, we target corporate travel, but we still work with individuals; you just need to click the Get Started button and we ask if you’re an individual after that. This pivot of sorts came from the fact we can deliver significantly more value to corporate customers (more customer value = more conversions, retention, referrals = better business & happier team). Consumer travelers typically only want the lowest price. If their “price to beat” is on a low-cost-carrier, we can rarely help. That becomes a dissatisfied customer despite us explaining “we’re here to help with your next trip”. Corporate travelers have greater requirements such as convenience, comfort, miles, hotels, perks, expertise, emergency response, off-site planning, large groups… the list goes on. With consumer travel, we were using a small subset of our tech and expertise; with corporate travel, we use everything and constantly need to expand our tech and expertise.

Hope that explains everything. Happy to answer any specifics about finding travel deals, since that’s what we do every day for 1000s of customers.

The problem lately is that airlines are still cancelling and rescheduling a lot of flights. So even if you book a particular flight there's a significant risk that the airline will bump you to a different one.

Google Flights does this for you. It can both show you actual prices per calendar month, and predicted price rise/fall. It even highlights the lowest price dates. And you can sign up for e-mailed price alerts.

Sigh downvotes on HN.

This is correct. Google Flight is amazing at tracking flight prices over time and lets you see dips in the past on a readable chart.

Something that they could make easier would be to forecast exact price changes based on the same flight flight on other dates.

> This is when I wondered - could I make a startup out of it?

Usually the algorithms change when you do that. I used to scrape data and get a lot of cheap flight tickets, but the difference is that I didn't blog about how I did it, nor did I provide services for anyone :)

> So I booked my flight immediately. Knowing exactly when to book definitely felt like magic.

This is the part I can't do. I never get the best fare, let alone those occasional $300 round trip to Europe fares, because I care too much about the specifics of the flights.

A bad flight time can lose you part or all of a day, leave you with a ruined sleep schedule, force you to start/end your trip at an absurd hour of the early morning, you can end up sitting in an horrific middle seat by the bathroom, or flying on a bottom-of-the-barrel airline and so on. If you can live with all of those compromises, it's great! If not, you end up paying a more "normal" price for your ticket.

Even just a little bit of flexibility can save you money. One EU vacation I was able to save $500/ticket by leaving early in the morning and flying to the hub airport, paying the $50pp for the nice airport lounge, and working all day (those lounges are built for business travelers are a lot like co-working spaces) from there. I finished working, had another 'free' snack, got on the plane to the EU, and started my vacation.

You could put a price on those, and code your algorithm to select the best compromise for you.

I believe the startup mentioned was Forecast, which was acquired by Microsoft and then nuked without (AFAICT) the tech actually landing in any MS product. Maybe it was just threatening Expedia or something...

Farecast, but yeah.

I think for a brief period it was integrated with Bing's flight search tool, and then killed.

Reminds me that in 2019 I flew 17 times to the balearic islands from Germany and back for prices ranging from 1.99€ to 6.99€ per flight, it's about 20€ to 200€ right now. Missing the travel..

I thought ticket prices were also correlated to petrol prices. And that since airline companies buy petrol in advance, in order to predict prices you'd have to factor in petrol prices X days (months?) prior to flight date.

I enjoyed this post however was hoping the result was going to be more interesting than the rather obvious "buy a few months early and keep looking at prices in the meantime."

This is such a weird thinking. If he put average market rate for the time spent on it, I am sure it wasn't cheap in the end. Why so many people don't value their time?

Author here. Your thinking is equally weird to me. I value my time for sure, but isn't there a cost in not persuing what I'm genuinely curious about? What if a successful startup had come out of it?

By the way, this took place in 2011-2012, when Google Flights didn't exist.

I often find that flight prices can be influenced by what you have looked at previously (other competitor, clear cache and cookies etc). It's quite a shady practice.

As somebody who is traveling out of the US for the first time on a South America trip, I found this article both helpful, and technically illuminating! A great read!

ymmv but I've found Autoslash to be by far the cheapest option for car rentals. Not sure it can be scraped though would be interesting to include it.

His results jibe with the advice I was given by a frequent traveler: book your flight about 2 months in advance.

What is the best time to buy rail tickets in the USA?

Amtrak tickets are sold in buckets and don't price fluctuate much. If you are booking in advance more than 14 days and Saver tickets are available those are the best deal. I have also bought train tickets a few days out and they were cheaper than last minute flights.

Almost uniformly earlier is better. There are some specials but you're almost always losing if you wait.

is this about some excursion/idea from 2011/2012? I know it's just been posted but it's about a pretty old thing

can mark it (2012)

Author here. This story took place in 2011-2012, but I wrote this post in April 2021.

I'd be very interested to know how patterns changed between 2012 and, say, February 2020. I bet watching such data as the pandemic eases will be vastly interesting too.

I don't have any insights into the post-pandemic picture, but up until early 2020 when I was working with flight tickets, the general pattern looked the same: roughly 90 days ahead is the best time to book.

I think it generally depends on the market and on the route. I got some cheap flights in South East Asia in the week I flew, with prices being lower than average. This led to me postponing “what’s next” decisions to the last possible moment.

Yeah, I think it applies mostly to long distance flights. You can see the effect you just mentioned in the graph in the article! The price < ten days immediately before a trip, when it's steadily creeping up, can still be below the long-term average, cheaper than almost any other period beyond the 30-60d window.

If you're going somewhere anyhow, housesitting is a way to get paid to live in someone's pad. Cheaper than airbnb. :) Hostels otherwise.

Freighter cruising is slow-paced, DIY/BYO entertainment, interesting, and cheap, but you'll typically have to live without as much internet.

Eurorail young adult pass if you're younger.

Get paid as a vehicle courier to drive cars from one place to another.

If you fly a lot a lot... https://www.prioritypass.com for near universal airport lounge access

Housesitting opportunities in places you'd like to visit are extremely rare. I used to live in a mountain resort town, and there were posts in our housing FB group every week seeking "housesitting opportunities" (read: free lodging during their ski vacation). No one ever replied.

Freighter cruising is much more expensive than flying for the same distance, but cheaper than an actual cruise. You could probably simulate the experience by living in a motel 6 with a stranger (since you won't get your own bunk) and getting food from Denny's 3x a day.

I used to have Priority Pass as a perk of a corporate card. I was unimpressed with the priority pass lounge in SJC. Filthy, bad food, mediocre service. Far worse than Centurion and Delta lounges.

Their lounges in other aiports seemed to be closed whenever I was in need of them.

Based on that, when we switched to a different corp card, I did not try to get a personal card w/Priority pass access (nor did I buy my own membership).

Priority Pass is great internationally. In the US, the lounge access is usually fairly mediocre, but the airport restaurant access they have at some airports is great - up to $56 credit for food and drink each visit if you're there with another person (e.g. https://www.prioritypass.com/en/lounges/usa/los-angeles-ca-l...). It's been a while since I've last been on a plane thanks to the pandemic, but I was generally getting a few hundred dollars worth of value from the restaurant access alone each year.

Yeah, Priority Pass lounges are generally more useful internationally given I (normally) have a Star Alliance lounge pass anyway.

Dining is very hit or miss. For example, there is (was?--who knows) a specific breakfast option at my usual home airport/terminal that's a great deal but I've not really found a use for it otherwise.

When you're coming back from a busy trade show or convention like Defcon in Vegas, that Centurion lounge is almost essential for a decent place to sit, eat or nap in McCarran.

And using Delta's lounge would mean having to fly Delta. Ew.

It just depends on one's use cases. If you're primarily traveling to large conferences such that airports are especially packed, just Priority Pass is probably a poor match. But that's not everyone's scenario.

I had Eurail part of one summer when I lived in Germany. I was between broke and cheap so would sleep on overnight trains, even taking them partway out of the way and then back. I think I travelled something like 23 nights and paid for 5 nights of hostels in total.

Do you have any resources for someone interested in doing freighter cruising? I imagine right now with the mess that is international shipping, things aren't so good.

PriorityPasss is free with certain credit cards.

It's free with so many credit cards that the value has been somewhat reduced - partly because lounges have gotten more crowded, and some partner lounges will reject Priority Pass holders if they're at capacity (since they'd prefer to serve ticket holders on their own airline first).


I know Sapphire Reserve offers it, have to remember to renew it each year though

Yup. $550/y. Also interesting perks:

- Pre check fees

- No foreign currency tx fees (like my uni's ATM card)

- Lyft pink & bonuses

Other cards:


The Select version is pretty sweet, almost like Prestige.


I don't know why almost everything is more expensive Canada... It's about the same distance from Montreal-Vegas and FortLauderdale-Vegas but it only cost about 142CAD round trip when you come from FL. The food in Canada is also very expensive... I pay about 1/4th what they pay for a gallon of milk for example (and I won't talk about the gas).

Taxes, a bunch of which are tariffs at the border or built into the price like the gas tax, protectionism, laws and a smaller market.

I don't think it's that simple. Even local produce is exceedingly highly priced these days. We've no shortage of produce, and there's no real protectionism going on there. And AFAIK there hasn't been any tax changes on those kinds of goods yet the prices are ever higher.

Also, I guess milk is not a very good example because the government has a minimum price set on milk, at least in Quebec.

It's a good one I'm thinking, because laws are literally making it more expensive. There are a bunch for other food items. The gas tax is higher so gas is more expensive, the cell phone market is an exploitative oligopoly even more than the USA and thus the prices are some of the highest in the world, and so on. The countries economy is now dependant on the RE sector, so that is even worse than the USA for many.

TBH if the USA got universal healthcare, the advantages of living in Canada would be slim.

For EU and Asia traveler, that trip seems very expensive. My cheapest trip ever included 7 flights between 3 continents for 90 euro.

Because Canada! Canada is often more expensive in almost everything. If you think about the size of the country and population density, then it makes sense.

Author here. You're absolutely right about Canada ;)


was all the work that went into this project factored into the amount of money that was saved?

In the article, the author covers this, saying the technical facets of doing this were worth more than the money saved.

In other words, the author tallies the work and learning that went into this as a positive benefit, not a negative, as you may be alluding.

I think he enjoyed doing it, which is added value to one's life.

Yeah, I have a friend that spends hours a week planning this kind of stuff out. His hobby is putting together vacations from credit card points as cheaply as possible. TBH I think he actually enjoys the scheming part more than the actual trips.

My father still enjoys clipping coupons and views it as therapeutic. He also enjoys the act of saving a few dollars here and there because it gives him the same dopamine rush that it did when he those dollars were relatively important to his overall net-worth. To many of us, the act of saving money is more exciting than the money itself.

I can definitely relate to this. I've spent countless hours optimizing my groceries and trying to get them as low as possible. I could easily spend several times as much without much financial impact, but I enjoy it as a way to derive satisfaction and mindfulness from what's otherwise just a mundane and repetitive chore

I think the question is, if he didn't enjoy doing it, would it still be worth it, for examples for others that might view it as work

I'm the author of the post. I can confirm that I 100% enjoyed it.

I usually view such things as work, but thank you for giving me another perspective. Maybe next time I'll make it an enjoyable game.

Applications are open for YC Summer 2023

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact