One thing I didn't realize when I started pitching the first book was that there would be "passive income" in addition to the book advance and royalties.
For instance, I've had three foreign-rights deals for "Experimenting With Babies," and the only additional work I had to do was put my signature on some paperwork.
And I have Amazon referral links on both websites, pointing to each book on Amazon. Those links generate a monthly average of about $40 in commissions per month, although my monthly high has been as much as $630.
I only read the first two "experiments" but it looks awesome! Waiting for a child of my own to try all these experiments on.
I'd love to hear about the history of the book - how did you decide to work on something like this?
I got the idea for the book while rocking my son back to sleep in the middle of the night. I realized that I had been doing lots of informal experiments, and I thought it would be really cool to adapt real experiments from various fields of child-development research so that parents could perform them on their own children, with no special equipment needed.
For "Correlated," I used a lot of natural-language generation, so I suppose you could say that my editor was Sublime Text, at least for the drafts. Then ported into Word format.
If you're hoping to get your book in bookstores, get an agent and work with a traditional publisher. Actually, I think going the traditional book-deal route is normally a better bet than self-publishing, unless you expect the vast majority of your sales will be digital and you have a large pre-order list that gives you an assurance of a larger paycheck than any advance you're offered.
Of course, authors must always be their book's best marketer, but having a publicist takes a load off your plate. In my case, the publisher's in-house publicist handled pitching media outlets so I didn't have to.
If you're going to spend money to publicize your book, spend it on pitching media outlets. A single mention in a well-read magazine or newspaper can give you a real bump in sales.
6 months: Regularly covering server expenses (which were ~$50-100/month at that point).
18 months: Would have paid for me to live nicely on the beach in Thailand.
30 months: Would cover my rent (and nothing else) at a nice apartment in a major city.
40 months: Passed the monthly take-home pay from my first (non-software) Engineering job out of college.
60 months: About what I'd have been making had I stuck with that first job out of college for 10 years.
80 months: Roughly a Senior Dev salary anywhere but the Bay Area.
As I noted a few years back for the first version of this list, this is for a SaaS subscription product that I built with the explicit goal of having a low-level income stream that I didn't have to put much time into. Early on, there were periods where I worked 80 hours or more per month to get the infrastructure ticking away to my satisfaction. These days, it requires maybe six hours of my attention each month.
This year, though, I've been back to full speed (meaning high single digit hours per week) building out and releasing a bunch of new features.
For the most part, the people who request the Cheap Bastard Plan don't have much in the way of traffic, so it's not particularly expensive to service them. Every once in a while I'll get a request from somebody who's a bit "cheap"'er than normal, asking for an upgrade after posting a comment to an online forum or blog entry, or even just a tweet. But for the most part people tend to have nice things to say about the product, and proceed to say them.
One possible application might be recurring revenue stats (growth, churn, etc). There are some solutions for this but they all depend on certain billing providers. Would be nice if you could just upload a .csv file of all your transactions, tag the columns, and get a nice report.
Out of curiosity does anyone know of a similar service for Google Cloud Storage? Really bums me out that they don't break out bandwidth per bucket.
They've been pretty bad the last few months. I think it's because the server was overloaded and response times were getting really bad. It was running on a GoDaddy $70/mo VPS with IIS, SqlServer. But that server was also hosting an Umbraco site and a WordPress blog. The PHP process was taking up 99% CPU nearly all the time.
Now I have it running independently on a GoDaddy VPS and all the static resources are on Amazon CloudFront. It is much faster.
My wife says the designs we have are out of date and we need to make some newer designs. This involves going to Target, looking at the greeting cards, place mats, napkins, and other nick-hacks to get ideas. Also, Pinterest is great for design ideas! Then, opening up InkScape or a D3 console and creating SVG color-in templates in the site's specific format.
| Mon (desc)| Sales |
| July | 128.70 |
| June | 227.45 |
| May | 124.65 |
| April | 301.50 |
| March | 274.40 |
| February | 287.35 |
| January | 415.25 |
| December | 128.70 |
| November | 175.65 |
| October | 188.60 |
| September | 132.75 |
| August | 330.25 |
| July | 343.20 |
| June | 297.45 |
| May | 505.90 |
| April | 351.30 |
| March | 484.05 |
| February | 188.60 |
| January | 248.50 |
| December | 38.85 |
| November | 155.40 |
| October | 89.85 |
| September | 209.65 |
| August | 179.70 |
| July | 299.50 |
| June | 329.45 |
| May | 229.50 |
| April | 279.45 |
| March | 419.15 |
| February | 249.45 |
| January | 149.70 |
| December | 119.75 |
| November | 199.60 |
| October | 109.75 |
| September | 99.80 |
| August | 99.80 |
| July | 70.80 |
| June | 25.90 |
| May | 25.90 |
| April | 38.85 |
| March | 0.01 |
Also, the number of template available seems very low. From your home page, if you add up the numbers under "Categories", you only have 10 templates to choose from? You need to get that to 100. Seriously. This is like a business card creator site - you need lots and lots of choices, and people will buy.
Not many want to custom design a complete cupcake wrapper themselves. Just pick a nice baby design and add text to it for the baby name.
Email some of your customers and ask them how you can improve.
My 2 cents. Congrats on the success, and good luck!
But, it's been on my to-do list for over a year to build a wizard on top of the custom designer with a step 1) choose a design, step 2) upload photo, step 3) enter text, type of experience.
Made a portfolio website for my girlfriend. Got positive feedback, refactored into Wordpress theme and published on ThemeForest. Not 100% passive as I spend 3-4 hours per week for answering support emails.
ThemeForest is a perfect place for passive income if you are a website developer. At first it challenges your skills as you need to create the concept, design it and code it. Then it challenges your business, marketing and support skills. You become a one man factory and learn a lot.
Definitely not an area your average web-developer can just drop into. I can definitely write the code but you also need a good artistic/design mind. Just to make everything more coherent and to create a real theme that runs through the template.
I've been considering doing the same thing with some of my sites. Do you have any tips on refactoring something we've designed and selling it on a theme marketplace? Are there specific site features that sell better than others and/or are requested a lot? Do themes with wordpress/php included sell better than ones without? I'm very curious - thanks!
If you look at other themes on TF you will notice how many features they have. Building your first theme with the same amount of features would be very time consuming. I went with "Getting Real" approach and focused on doing the fundamentals right. At the time I launched there were no customisable fonts, colors or sidebars (something that most of other themes had). But it still sold well, because people liked the way it showcased their portfolios.
Do a Wordpress theme. It sells much better than HTML only and selling price is 4 times higher.
I've contemplated converting some of my custom WP themes to sell on ThemeForest but I didn't think it would be worth the time.
edit: I often wonder if it would be worth it to try to compete with theme clubs. They seem to make a killing on recurring revenue and release a couple of themes a year.
There are a couple of high-selling authors on TF that established their theme clubs. They build up customer base using TF and then invite people to subscribe for a yearly fee to get access to all of their themes plus the ones to be released. I guess after you reach certain amount of customers such model is much more profitable.
Eg. http://www.themezilla.com/ and here's a link to their TF profile http://themeforest.net/user/OrmanClark
In general people spend a lot of money on themes. I think you might be better off competing with themeforest or more likely, any of the number of bootstrap theme website popping up.
You pay yearly to access to a bunch of quality themes. They pay out 50% commissions (and on renewals too) to affiliates but they have 200k+ plus users. They have to bring in a couple million a year.
I believe they started out at much lower prices and started raising it as they released more and more themes.
Direct link to the demo: http://inthe.me/demo/fluxus/
The interesting thing is that you can't control the price of your theme and it is set at the time of publishing by TF. Price range for WP themes is $35 - $50
Pluginbag offers 80% to the seller with No Exclusive lock in
Shoppers will benefit from the latest, well managed and quality work of the sellers.
PS: I'm the cofounder at pluginbag.com
Hope it works out, sounds like it's a better deal for sellers (which often makes buyers happier in the long run).
I've never had an idea good enough to make an app out of, or build a company around. So instead, I started investing a small amount of my paycheck in to my brokerage account. Buying lots of stock in Dividend Kings, I've earned $25 this year, with another $20 through October. It's not a lot, but I'm fully thinking long-term.
I guess the other thing I'm doing is finally putting money where my mouth is and putting money into companies I think will succeed in the future.
Getting $25/year would need around $3000 in the account. Although it might not increase much over the years.
The US has had very low inflation in the last decade or so with very small deflation in 2009. but interest isn't beating inflation here either though.
As far as "high yield" savings goes, for a normal savings account or money market account you'll be looking at 1% being the max rate right now, if you can find it. Last I took a glance I saw .95% being the highest. Those are for online banks. I get .85% with Discover Bank (online savings account). I also have a 17 month CD that earn me a whopping 2%. That was a one time special my [brick and mortar] credit union was offering. Those accounts are FDIC (or NCUA) insured.
Let's, for example, look at the history of credit cards. I am sure you can agree that the 30% interest rate charged today is unreasonably high. It wasn't at a time, and lets look at how it got that way.
Back in the late 70s/early 80s we had a recession with double digit inflation while at the same time all states had usury laws that capped credit card interest rates. Inflation was so high that inflation surpassed the highest interest rates companies were allowed to charge. Citibank was "going broke" with this model - they were actually losing money lending at that interest rate at that time. Citibank then convinced South Dakota to drop is usury laws on credit cards and Citi would move there in order to charge an interest rate that beat inflation. Citibank moved there and overnight the stage was set for the US credit card industry to now flourish. "All of their senior people used to say it,'' [then governor of South Dakota] said. "That South Dakota saved Citibank. I believe it did. That South Dakota saved Citibank.'' It was a result of an economic recession with high inflation. There was a Frontline special years ago about this - http://www.pbs.org/wgbh/pages/frontline/shows/credit/more/ri... - though it is outdated, since credit card legislation has passed that addresses a lot of the topics brought up on the show. you can watch it online for free - I highly recommend you do.
Delaware and Nevada followed with similar legislation, so that's why most (all?) credit card companies have a return address in SD, NV, or DE.
However, we are no longer in double digit inflation but the old interest rates and legislation stand, for the most part. New laws are slowly reeling in on some credit card practices to keep up with the economic times and current circumstances.
*Disclaimer: I have no idea about the economic situation of Ukraine. I am just making a point about judgements of different times/economies.
Mutual funds may be a much better option, though.
So yeah the returns are pitiful in a savings. The rates on CDs are lower than the one on the savings account.
In the short term it looks like a bad idea, because you could have more income coming from your dividends, but when a crisis or something hits, it's worth it.
A dividend stock is likely to beat inflation, (but not with as much growth as a growth stock.) Theoretically, if you're only using the dividends, it's just as good in downturns (as long as it's not GE/GM/BAC with huge non core financing arms).
My risk adverse holding is a major, regulated, electricity provider. If it goes out of business, it's likely that I also don't have electricity.
If you're talking something like a collapse of the entire economy, then yes, tangible assets like gold and real estate are much better. It's not impossible, but I don't know if it's especially likely that's going to happen....
That said, I do invest in gold/silver and real estate as well for various reasons. I also invest in dividend stocks for other various reasons. They all have a place in my strategy.
I haven't done much research on emerging markets, but isn't that a very high-risk/high-reward investment? For now, while I'm still stuck at my job and not yet "rich" (by my conservative definition) I'd rather mitigate my risk and have some control over my investments -- I plan to be successful and well-off, I'm not just hoping that I get lucky and one of my investments' value goes through the roof.
(I'm not criticizing and I didn't downvote you. I'm actually interested to hear others' investing strategies, maybe I can learn something new!)
In theory, dividends are a great source of passive income, but with effective yields of 2-3% you'd need a lot of capital to generate any meaningful income, i.e., a $1M investment would pay around $30,000 annually.
Dividend stocks have never performed that well; they never appreciate 10-20x like certain growth stocks, they usually underperform relative to the market, and when the market declines they all go down just the same.
Here's an example: over the past two years P&G (PG) and Coca-Cola (KO), two dividend stock favorites, are up about 20% and flat respectively. The S&P 500 index is up 40% in the same period, Facebook (FB) is up over 200%, and Tesla (TSLA) is up over 700%.
To get that 700% increase in Tesla, you would've had to get in early; and how do you know at that point that the stock's going up or down?
While I'm sure plenty of people actually do make significant money on growth stocks, it's about appreciation and capital gains. Worse, it's about appreciation of an asset you don't have control over. It's got better chances than trying to win the lottery, I guess, but you can't really know what the future holds. Everything I've heard about other people investing in the stock market (and hoping their portfolio goes up) usually involves wins and losses -- which end up cancelling each other out. You also have to realize the gains to get them. If you don't sell when the market is up, you might lose when the market goes down.
Dividends (not the value of the stock, but the dividend it pays), however, tend to remain stable, even through crisis situations like 2008.
Now, I've read about some pretty complex investing strategies that involve options and all sorts of hedging -- strategies that basically ensure a return by mitigating the risk. But that takes a lot of learning (and time) and I'm not really a stock guy. I feel like my time is better spent focusing on big wins in other areas (where I have more knowledge).
You mention that dividend stocks don't perform well -- but the purpose of investing in dividend stocks isn't usually about watching the price of the stock rise. It's about the dividends -- which are nice by themselves, but also usually rise about 15% a year for those companies. It's also about DRIP investing -- reinvesting the dividends rather than accumulating or spending them. Between DRIP and annual dividend increases, the stock compounds on itself. With any compounding investment, the key metric is time -- so starting early and letting it compound over your lifetime is very beneficial.The idea isn't about investing $1m immediately for $30k/year immediately. Invest slowly over time to have $1m worth of stocks paying $30k/yr (while not actually paying that full $1m, since much of it came from DRIP and hopefully dividend increases)
However, I'm not saying you're wrong, this is all just my opinion. I'll admit my stock investing strategy is very conservative, but like I said, I'm not much of a stock guy. Until I discovered dividend investing strategies, I thought about investing in index funds -- and even before that, I avoided the stock market entirely. I'd much rather own and control my assets, which is why I'm bootstrapping a business and investing in rental real estate primarily -- and reinvesting the income into dividend stocks (when it's an attractive investment) for sort of a stable "base-layer" of "backup" income (down the road -- after compounding) that I honestly hope to never end up using.
EDIT: I just wanted to give an example.
Say you have a stock that's worth $50 and pays a 3% dividend ($1.50 per share). You buy 1 share per year for the next 30 years.
Let's assume no growth -- the stock stays at $50 per share and 3% dividend for the entire 30 years. So you've spent $1500, total, on this stock over that period, and purchased 30 shares. However, with dividend reinvesting, your total holdings at the end of that time are 47.58 shares (you can have fractional shares with DRIP) and the total value is $2,378, and pays a $71 annual dividend. The value of the stock, with no appreciation whatsoever, is about 60% higher than the total purchase price ($1500), and the dividend it pays is about 5% of the purchase price.
Now add a 15% dividend increase per year and an average 15% stock price increase per year (if the price remains stable, the math goes crazy -- you end up paying $1500 over 30 years and have a $2m portfolio paying $4m in dividends!). You pay $59k over 30 years for 1 share per year of stock. At the end of the period, you end up with 7 extra shares and your portfolio is worth almost $370k -- that's a 500% increase in value over what you paid. You also receive an $86 annual dividend per share, and over $3k total per year -- again, a 5% dividend at the end.
These are very simple examples, as well. Realistically, there are a ton of extra variables. You probably buy more stock as time goes on, simply because you make more money. You might also buy a whole bunch more during market crashes, reducing the average cost per share at the end of the investing period -- or you might buy less when the market's soaring. Stocks might stagnate, companies might go through hard times, etc. forcing you to stop buying or outright sell. Plus there's inflation and all.
You probably can also charge a larger than average security deposit to weed out the people with cashflow problems. Most states have a cap on amount of security deposit collected, I know here it is twice the monthly rent if under 60. Otherwise the cap is one month's rent.
Here's the rub: You usually gotta have a great place to rent that attract such tenants.
DISCLAIMER: I am not a landlord but I am considering becoming one. Yes, I FULLY know the risks, my parents were landlords for over a decade. So I know exactly what NOT to do as they only made pennies. My grandparents are also landlords and make plenty of money on their rental properties, so I have a positive model as well as a negative one. :)
My TOWN even has a whole book of additional rights for tenants/obligation for landlords in addition to national and state regulations.
Being a landlord is serious business.
Got to be careful with drugs because the police can confiscate the house via asset forfeiture. One tenuous link between a drug dealing tenant and my bank account and the department has a new vacation home.
Probably not though since I live in Brooklyn. :(
Sales are online only (have not pursued wholesale yet) and is enough to live off of if all else fails. After 6 years we are have about $600K in total sales.
Great animated GIF on the home page!
(There's more than one you know!)
The first week I made $1200, the last month I made around $450. Things have been slowing down with some personal things going on, so it's been mostly passive as of late. When I launched I had some real speed issues and a lot of optimizing to do, which was incredibly nervewracking as it's my first web app built on PHP and the first project I did that uses a database.
edit: forgot the link: http://space.galaxybuster.net/
Sales from that are well over 10K USD at this point. A lot of that was over the launch week, I've not had a huge amount of time to devote to marketing it over the last couple of months as our main business (which was a side project until it took off) has kept me busy, so it really is passive income at this point.
I wrote up on my blog about creating the various versions http://rachelandrew.co.uk/archives/2014/01/07/html-epub-mobi...
I've also recently presented on how to build books in CSS and HTML and the slides and various useful resources are here: http://rachelandrew.co.uk/presentations/css-books
The fonts and page layout make for high quality books.
Using pandoc you can convert pretty much any modern markup language to .tex (I don't recommend .tex as the source format, as it might be difficult to get used to if you don't have experience with it + it is not trivial to produce .html/.epub from .tex sources.
Keep up the good work.
You need to be building an audience for your book long before you actually launch it if you want to have a decent launch. Nathan Barry writes some good stuff about this, check out his book Authority: http://nathanbarry.com/authority/
I've written about it before, if you want to look through my history.
Mind sharing what the cleaning company is? You appear to be in the UK, and I will soon be in the market for a cleaner.
I'm assured things are organized now but its still a little nerve wracking. I know lots of people that would love to be able to reliably rent bikes in India and have often thought about doing what you have done. Your interface looks very professional and gives confidence to the user.
I live in Mumbai, do you have thoughts on expansion?
How do you market?
edit: to mention that it bounces around between $1.50 a day to $2.50 a day based on usage
What kind of plugin is it?
How do you monetize it?
W3Counter (https://www.w3counter.com) meanwhile generates less than 10% that revenue from 100x the users. They're really similar services fundamentally, but worked out very different. W3Counter ends up being used by hobbyists that want to see vanity metrics like page view counts going up, most of which will not pay for analytics, while companies eagerly pay for Improvely as a profit multiplier for their online marketing.
Aside from those sites, not much has changed. I have a few e-commerce stores that essentially run themselves as passive income, and a steady stream of commissions from various business referrals I made years ago.
Support is low - though it took a while to build the initial technology. I get a lot of traction from realtors and lawyers. I've tried paid advertising but the conversions are too low to make it worth it.
Initial goal was "vacation money", and it's currently on track to hit that level next year.
I've had a similar service, http://dbinbox.com/, slowly growing with entirely free plans for the last ~year and a half up to ~25k users and am about to add premium plans.
The site is a bit lacking in documentation (typical side project issue). It's $3/m or $30/year. I get a good mix of both types of subscriptions. I figure the price is low enough that it's not a barrier to entry for the majority of people. I also need to document better what premium accounts get you (ability to upload to different folders, etc).
I experimented with adwords and stumbleupon but nothing caused enough conversions to be worth it. Every now and then I turn adwords back on to play with keywords a bit, but it's just not worth it at the low price point.
No it isn't :)
The initial time outlay was quite large, but it was always approached from the point of view of generating a lot traffic to get the payback.
Won't share the link as it's a competitive niche.
Is the content in English, or a foreign language? Do you get most of your "long tail" referrals from google.com or an international version?
I suspect there are a lot of wide open playing fields for content sites in foreign languages that simply replicate popular US based ones.
Can you talk about this?
Also, how many ads and what formats/sizes work best for you?
For automating scraping/spamming protection, I would consider something like CloudFlare Security though, my own tools are good enough for now, but I would still be vulnerable to a DDoS or a botnet scrape - it's enough to stop one-man scrapers but I'll need something beefier soon.
Ad formats that seem to work best: 728x90 by a long margin. I generally top and tail the content section with a leaderboard ad. I do serve different sizes for mobile etc, but the leaderboard works way better. I've also experimented with skyscrapers and boxes, which performed very poorly (skyscrapers especially).
Email in my profile if you are interested in details.
I've posted this before, but I wrote up some thoughts about things I've learned about launching a side project here that you might find helpful: https://medium.com/@mjwhansen/things-ive-learned-launching-a...
* Google's free tier is 2,500 a day. But if you need more than that, you have to sign a yearly contract ($10,000+). Our pricing is 2,500 free a day with additional lookups at $.001 each.
* We don't place any restrictions on our geocodes. The major providers often a lot of restrictions on how you use their lookups, like having to use it with a particular brand of map, can't use it in a backend, can't resell, can't store them, etc. Our lookups are completely restriction free.
* Related, at the enterprise level, we have an option for unlimited geocoding for $750 a month. Major providers usually have a daily limit for their enterprise plans, such as 100,000 lookups a day.
* We provide additional data that people often need along with lat/lon, like timezone, Congressional district, school district, and state legislative districts.
* We're non-developer friendly. We have a CSV upload option (http://geocod.io/blog/2014/04/30/csv/) that lets people upload a spreadsheet of addresses and download it directly from the same dashboard.
A big difference is that we're US-only for the time being. Additionally, it's worth noting that our data is close to Google quality, but not quite. They've embarked on an ambitious, admirable, and expensive quest to map the world and have cars driving around the globe daily. We don't.
Admittedly a lot of people don't read these fine prints, but they are overly restrictive for a lot of uses.
I looked at various services to do postcode/zip to lat/long and eventually settled on just doing it in-house using downloaded data. After a bit of data massaging it actually works really well.
Didn't expect much but amazingly it pulls in consistently $70-$110 a day (about $2,500 a month) for a few months now (not counting the initial release spike).
Game is free to download with 1 In-App-Purchase that unlocks the full game.
Thinking of doing an iPhone version soon which will be a bit more involved than a straight port due to the small screen size and different screen aspect ratio, but I'm currently convinced it will be worth it since the genre actually usually does better on iphone than ipad.
Just wanted to add this to counter all the doom & gloom posts about iOS games not doing well. If you have a great and unique product for a good target market with good retention and monetization, then you can still do very well without too much marketing.
(I actually run ads with about $4 daily budget. Not sure if it actually helps, but I think it does.)
Embrace the competition. Plan for it. Set time aside for it. Make it work for you.
I could try other ad channels, but I'm talking with a publisher who might be interested in publishing it so haven't tried that yet.
Might help your negotiations, or else you just got started more quickly than you would have otherwise.
There's about 10 minutes of support work per day, but besides corporate customers occasionally needing some phone salesmanship and some manual tweaking, everything else is automated.
Yes, it's probably more expensive than if I used EC2, but I've never been awoken in the middle of the night to need to reboot a server, troubleshoot a memory issue, or scale up my instances.
Effort is relatively low, a few weeks of on and off work to get it online, styling, moving servers a couple of times, etc. I need to move servers again I think, or at least upgrade all the software, it's kinda wonky for some people at times.
Not a lot but it’s something. And I built the validator without even thinking about monetizing so it’s quite nice to get rewarded with some pocket money.
It’s not 100% passive, as I do spend a little time maintaining it and adding new features, but what income is 100% passive?
I think £55 a year is best case scenario. At least it likely covers web-hosting costs.
While it's not a completely like-for-like comparison, I suspect it will be tough to justify $299 per single web site for many businesses that might use these tools in the first place. Personally, I'd want solid data about conversion rates to back up the marketing on the creditcard.js website before I'd consider spending real money on anything like this.
I was surprised since I'm a software guy I didn't write the book to make money, I just did it for something to do.
Although my software business makes much more money, I was surprised at how truly "zero maintenance" book sales are. My software I'm constantly fixing, tweaking and improving (which I enjoy). The book is just "out there" and is priced at $30 per copy. I sell > 1 per day.
The book: http://www.growthhackinghandbook.com
I've checked on App Annie ans your app seems to be around 500 (grossing) in health & fitness in the US. I find it a bit surprising that there are 500 apps in health alone making >2k month.
That said, my site seems to get picked up in an unhealthy number of "top free images for your website" type list articles - I'm not sure if other sites would get picked up at the same rate, but you could always try.
By end of august I'll be split-testing moderenizing it (it's not mobile/tablet friendly, backend makes it a pain to add content (especially text),etc) - I'm hoping making it nicer doesn't hit the income.
Now that my kids are old enough to travel easily, I plan on taking picture-taking vacations to some cool places once a year - and let them take a shot at learning photography on the job.
It's zero maintenance, and sometimes I even forget about it. I spend maybe 1-2 hours updating the website to a new Uglify.js version per year. It's a simple single file node.js app hosted for free on Heroku.
Honestly I just created it for myself back before Grunt, Gulp, etc. after searching for some simple online tools and not finding any that allowed uploading and combining multiple files together. The first version was PHP, and I switched it to a node.js app in 2011 after Uglify.js came out (there were a lot of problems with the PHP library I was using).
I created the website in 2008, so it's been going for quite a while, collecting backlinks and traffic ever since. I am not looking at the reports right now, but I believe it made less than $200 the whole first year I had ads on it (it didn't always have ads).
As for numbers: http://www.bingocardcreator.com/stats/sales-by-month Historically, multiplying by 60% usually gets a good approximation for profits.
My first side business was profiting $10k/mo but I ultimately lost it because of neglecting support emails.
I've checked again today, and now I don't get a SSL warning. I am pretty sure I've never visited your site before, so I don't think it's caching on my end.