Hacker News new | past | comments | ask | show | jobs | submit login
Why Doesn't Amazon's Price Sort Work? (jackg.org)
21 points by MagicClam on May 17, 2012 | hide | past | favorite | 29 comments

I don't work at Amazon but worked at one of the largest comparison shopping sites in a core search group.

Sorting by price is hard - if you really wanted to do a true price sort you end up with the long tail of products that match the term "ipod" (but are very loosely related to ipods) at the top of search results. Try searching for ipod in electronics and sorting by price.:


I get a usb connector, stereo speaker, some other mp3 players, etc. all among the top 6 results. Only 2 ipods on the first page. At least there is a link to a department containing just the ipods.

So in order to avoid doing really badly you don't allow searching by pure price, but rather use a combination of price and relevancy (and this can only take you so far as the results above demonstrate.)

There's no excuse like that for Amazon.

Ideally, you would click electronics category. Apple. IPod. Order by price. You didn't select category iPod accessories, so you shouldn't see them there

But some slob at Amazon sacrificed search by adding related crap

This is one of the few annoyances of shopping at Amazon. As a Prime user, I usually don't want to deal with anyone other than Amazon directly.

There's a search filter option to select "Prime eligible" items, but when you select it, the price sorting still seems to include Marketplace vendors. Selecting the "New" search filter does not help.

There's even a search filter for "Seller" that allows you to select only amazon.com, but the price sort is still wrong if this is selected!

(I understand that Amazon probably prefers that we stumble upon the marketplace vendors, but it's frustrating when you can't disable it even temporarily.)

Good question. Amazon is great for searching, pretty good for browsing, but pretty awful for browse-searching, where you're trying to narrow down results via search but still browse through them using various sorting and filtering types. The consistently awful price handling is the worst part of it.

I often find myself doing product filtering on other sites (yes, I feel a bit bad about this) and then (usually) buying on Amazon because of price and the free Prime shipping.

eg. I'll figure out what I want to buy for a new computer system on Newegg, because their combined browse-search is way better than Amazon's, and then take the final result and see if it is worth buying on Amazon via a direct parts name/number search. Amazon loses about 10-20% of the sales I would have otherwise just given them due to this when it turns out the cost to buy the item on the other site I was using is similar enough to the Amazon price. When the price is even close I favor the other site since they provided me a better UX experience, but I do admit that if the overall cost to buy on Amazon is significantly cheaper, I'll still buy from them.

Anytime you see something that's relatively easy to solve by a major company but remains unsolved, either you don't realize how hard the problem really is, or the company is profiting from their "oversight". Apple could easily make a 2-disk-drive macbook, but they don't sell that configuration.

I'm not so sure in the case of Amazon. Their requirements analysis process appears immune to customer feedback.

That was bothering me for ages. I wish someone from Amazon came out to explain what' really going on with broken sort.

I never really use sort by price because I find that the cheapest results are usually not very relevant, but I do have other complaints about sorting results on Amazon...

Why do I still need to select a department in order to sort? Does Amazon really not have the resources to index their entire product database (or at the very least just pick the department with the most results to save me a click)? And why can I only sporadically sort by bestselling/most popular?

I never really use sort by price because I find that the cheapest results are usually not very relevant

That's exactly part of the problem. If I'm searching for something specific like 'iPod Touch 32GB' I should not get results for $0.99 iPod cables and cases.

I wrote about this recently too, with some screenshots: http://chir.ag/201203161607

What I don't get is when I search for any product then select to filter by "Amazon Prime" I am still seeing results for items that are not Prime Eligible. Now you can't tell me that Amazon doesn't know whether or not they are fulfilling a certain product. I mean if they are able to display the Prime logo on the products page why can't they filter for only Prime Eligible items?

It works better with the prime only option selected, removing a major variable. I might wind up paying more for certain items, I don't care. I don't actually need the best item with the most features for the lowest price. The idea that I do is an artifact of incorrect cost/benefit analysis about the value of my time and mental effort.

At one point it seemed to me that the prices were sorted by the listed retail price for that particular item, and not the lowest offered price for it, or something along those lines. It's been years since I formed that wild guess, though. But it has seemed to roughly hold up when I'm (foolishly) trying to price-shop on Amazon.

Ex-Amazon engineer here. I worked on the smart refinements team, which shows relevant categories and refinements on the left hand side of the search and browse pages.

Broken price sort is a common complaint both inside and outside of Amazon. There have been email threads, tickets, and half working solutions to this but nothing -- so far -- has worked well enough.

First of all, no engineer at Amazon would tell you that the current state of price sort is acceptable. It is a well known problem that gets worked on from time to time (In fact, better price sort was going to be my next project before I left so, uh, sorry Internet...). The current price sort has been around for a long time and nothing has outperformed it.

Amazon can't sort by price well for several reasons.

1. What do you mean by price?

2. Low cost accessories

3. Bad item classification

4. More things that I can't get into

1. Price is hard to figure out. Do you want to sort by the base price of an item, the price plus shipping (which depends on where you live), or the price after discounts or specials? What about products that are sold both by Amazon and third party sellers, where the 3p seller charges less for the item but more for shipping than Amazon? Which price should be shown?

2. Low cost accessories dominate searches for a product. If you search for "iPod" in all-products search (APS, the default search on the front page) then you get pretty relevant results that span a few categories. To sort those you first need to select a category (we'll get to that later) and then sort by price. If you select electronics you'll see a few relevant results and a ton of accessories.

You could argue that Amazon should have better algorithms (and that's probably true), but there's only so much you can do. If you really want to sort by price then you shouldn't care about the relevancy of the results. To argue otherwise means that you won't have results that are increasing in price as you scroll down. You'll see more relevant but more expensive results at the front.

3. Both 3p and internal item-to-category classification continues to be a struggle at Amazon. I knew several people on the team that helped improve item classification while I was there and they did great work and made huge improvements to the catalog accuracy. Amazon has systems that learn the correct classification and suggest the correct categories to 3p sellers. Unfortunately, you'll still find sofas in the electronics category. This really screws up the results. Your outs are only as good as your ins.

4. There are some fundamental design choices that make solving this issue really hard. I obviously can't go into such fine detail, but try to appreciate that really smart people are working really hard so you can buy the lowest priced product as easily as possible.

In direct response to the article:

> Why would Amazon fail badly at something that seems so simple? The immediate cause is probably caching. Amazon likely has a task that periodically caches the low price for each item.

Well, caching is used extensively, but this probably isn't why the results look like they do. See #1.

> Tellingly, if you search for items without many Marketplace listings, the price sort is much more reliable.

Again, that's because if you exclude marketplace sellers the price is easier to calculate.

> Perhaps they can stop trying; why not just exclude Marketplace items from the price sort calculation altogether?

Seriously? Exclude a huge portion of all the products sold on Amazon? Crazy.

Price sort is hard. Just sort by popularity.

I think your points 2-4 all make sense, however:

    1. What do you mean by price?
    1. Price is hard to figure out. Do you want to sort by the
    base price of an item, the price plus shipping (which
    depends on where you live), or the price after discounts
    or specials? What about products that are sold both by
    Amazon and third party sellers, where the 3p seller
    charges less for the item but more for shipping than
    Amazon? Which price should be shown?
What possible reason would we have to care about the "base" price before shipping, discounts, or specials? When I say sort by price, I mean sort by how much money my bank account decreases by, and I think Amazon already knows this, because when you look at "New" or "Used", it sorts by base price+shipping, just like it should.

That being said, the other 3 reasons sound intractable, and are exactly the reasons I would have guessed.

Except that shipping is not necessarily obvious. There are several options (overnight, 2 day, longer) with different price points. Also, if you're a Prime member you get free 2 day shipping, but what if I'm prime but not logged in/using a different machine?

And setting a default shipping cost is likely to further confuse customers. E.g. if you show the cheapest option always, there will be a price bump at checkout, but you don't want to show expensive option by default because it raises all perceived prices.

> 1. Price is hard to figure out. ... Which price should be shown?

The numerical value that will appear on my credit card statement if I were to actually purchase that single item.

Any other value for "price" for that item is a falsehood.

2 and 3 are the same problem.

For #3, if it's that broken, kill it.

Always though Amazon were putting crap on the categories in the hopes I'd buy it.

Like markets puts peanuts close to beer.

If it's all textual search, and that bad, kill it.

It's only bad because they are lazy greedy slobs.

It's the easiest problem to solve. Just remove bad categorization.

Open Amazon, click any category. Let's say hdmi cables. What do you see? Probably televisions, screws, microwave ovens, inflatable sex dolls, anything!

They let bad Sellers fill their categories with crap. Now you can't search.

And that's some kind of difficult problem to solve? Give me a break.

Compare to google:


Equally bad results in my opinion. I guess they are lazy greedy slobs too.

What really gets me is when I'm on a site (Newegg does it too) and I search for, let's say, 4GB DDR3 1333. What comes back in the results? A $3000 PC that has two sticks of the RAM I'm searching for. That's not RAM. That's a product featuring that RAM. Or more to your point, search for HDMI and you get TVs and video cards that have HDMI ports on them. If I wanted to look for TVs, I would have said TV.

That's what I thought the article would say, too!

Actually, it's complaining that the items are not even sorted correctly.

Sort by price "high to low" and tell us if you see anything that doesn't look like an HDMI cable.

Sorting by most sold/popular is ok on the fist items because other ppl looked for the actual stuff and bought it.

but even that doesn't help on less popular categories

They probably found that it increased sales by 0.7%.

They found that quasi-random ordering increased sales? That seems odd. What algorithm do you suppose they're using to order results? Random number generator?

If anyone in the existence of the Internet was best suited to experiment with sorting, it would be amazon. A 1% improvement for amazon pays for a department of engineers.

A department of engineers that can experiment with advanced search.

In the article's example, 'ipod', I think amazon's strategy is clear. They are sorting lowest to highest of what they think you might mean by 'ipod'. Does the user mean 'ipod [touch]'? 'ipod [nano]'? Or maybe 'ipod [accessory]'?

If they did the 'proper' substring based search to create a set which was then ordered by price you would only see ipod accessories for the first 100 pages. Which would be prefect if 100% of people who searched 'ipod' only wanted accessories. Which is not the case.

So amazon is 'cheating' to show users what want to increase sales, even if it drives us engineers up the wall.

Patio11 would be proud.

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