I run <a href="https://IndieHackers.com" rel="nofollow">https://IndieHackers.com</a> where I interview developers/entrepreneurs about how they make money from their apps and projects. There are tons of examples there that fit into the "passive income" category as you define it ("making something that makes you money while you sleep").<p>A couple of good examples from the site:<p>- park.io (from Mike Carson) makes $125,000/mo taking domain backorders; he essentually wrote tons of scripts that buy expiring domains on behalf of his customers for $100 and that allow customers to bid against each other<p>- Instapainting.com (from Chris Chen) makes $32,000/mo allow customers to commission artists to turn their photos into hand-made paintings; it took him years to get to this point, but it's almost all automated and he rarely has to step in<p>Indie Hackers itself is my passive income source, although right now it takes a lot of work on a day-to-day basis. I'm writing a blog post about that that I hope to put up on my timeline (<a href="https://IndieHackers.com/timeline" rel="nofollow">https://IndieHackers.com/timeline</a>) by tomorrow. I'm doing just over $1000/mo right now, mainly from sponsors.
A stock portfolio that I've built through consulting profits is my main passive income source. Anything else is not really "passive."<p>This probably isn't the answer you're looking for, but in my view the average developer is much better off simply selling their time at the maximum rate and funneling the profits into a well-managed portfolio. The median outcome for this is much better than the story on most passive-income businesses.
I run <a href="https://www.goread.io/" rel="nofollow">https://www.goread.io/</a> which is a subscription-based RSS reader. It's open source and runs on google app engine. It costs ~$2k per year to run and I make between $2k and $3k profit per year for nearly zero effort. Stripe handles payments and app engine keeps the servers running.<p>I consider it a high success because for the amount of marketing I've done in the last 2 years (exactly zero), it still has paying users. If I did a few months of code improvements and marketing pushes I could probably increase that income a few times.
I have a card game business that's aimed towards women, PoCs & the lgbtq community - groups who aren't traditionally served.<p>Every couple of weeks I ship product to an Amazon warehouse and do a bit of advertising on Facebook. It brings in around $40k/mo and 3-4x during the holiday season.
I still get royalties from programming books I wrote about ten years ago - the content has been updated by other authors in the mean time, and the corresponding royalty split has declined, but I don't do anything active either.<p>On the not-quite-as-passive side, I have an iPad game that I had basically left out in the Apple App Store for several years, where it sold with no involvement or investment on my end. Only recently, Apple required all app developers to resubmit their older apps or face delisting - in my case, it involved updating cocos-2d to support the latest ARM architectures, and making a whole lot of changes for everything that had happened in iOS in the past couple of years.<p>I also run a small API-as-a-service, which runs on reliable infrastructure, and doesn't take much real work to monitor and/or run.
I run <a href="https://www.weheartswift.com/" rel="nofollow">https://www.weheartswift.com/</a> the first site dedicated to the Swift Programming language.<p>I've wrote a book that teaches people how to code in swift from the ground up. <a href="https://www.weheartswift.com/swift-programming-scratch-100-exercises/" rel="nofollow">https://www.weheartswift.com/swift-programming-scratch-100-e...</a><p>I've also made an exercise platform similar to codeschool/codecademy/etc that is available as a mac app using playgrounds or online by using our swift sandbox <a href="https://www.weheartswift.com/swift-sandbox/" rel="nofollow">https://www.weheartswift.com/swift-sandbox/</a><p>The site generates about 30k/year in revenue growing at a steady pace. Operating costs are around 10k / year for servers/software/subscriptions/marketing.<p>I need to spend about 2 weeks yearly updating the book/app to the last version of swift. I also spend about 5 minutes per day replying to customer emails. It's not that passive, but really close. (ignoring time spent developing products/book)
Portfolio of index funds based on <a href="http://canadiancouchpotato.com" rel="nofollow">http://canadiancouchpotato.com</a><p><pre><code> 25% TSX (Canadian market)
25% S&P500 (US market)
25% MSCI EAFE (Developed market excluding Canada/US)
25% Fixed Income - cash,bonds,'high' interest savings account, etc.
</code></pre>
Requires about 4-5 hours of time once per year to rebalance portfolio and update some partially automated Google Docs files to track performance.<p>Works for me...also planning to get a rental property at some point.
Small tools and web apps that provide a quick solution to very niche problems. Mostly aimed at business. Primarily based on obscure forms that occasionally need to be filled out for shipping. If I find myself googling something but don't find a great fit for what I need or many relevant hits, I look into building it. Or if I find myself manually gathering and formatting data or info, I see if I can automate it. Some end up being useful/found by others. Some don't. I currently see about $300/mo through adsense. A few of these things could turn into something more if I was ever motivated to do so, but would no longer be passive. Some probably not. Most interesting is seeing what takes off and what doesn't and trying to apply that to duplicate the success.<p>I've tried a couple affiliate projects, but have not found a great fit yet.
Odd how few seem to mention property (real estate)? Even those alleging actual returns worth a damn on stock portfolios. Surely the most obvious route on the planet is property. For two reasons:<p>1. It's leveraged. I.e. a bank will usually give you a 4:1 loan (mortgage) to buy property. Interest will usually be close to the central bank rate, so it's about as cheap as a loan gets, especially right now. If you then rent the property you are receiving a monthly return on the leveraged sum having only invested the deposit...<p>2. Property is an appreciating asset (US,UK,China,FR,etc). It's a systemic matter in many countries because it ties in a large part of an individuals net worth and retirement expectations.<p>Your 200k leveraged with a mortgage will net you more than most stock portfolios unless either you're Renaissance Capital or you just like a gamble.
I run <a href="https://mapchart.net" rel="nofollow">https://mapchart.net</a> which is a map chart creation tool. You can quickly create a map chart of World, USA, UK, Europe and more with custom colors and descriptions.<p>It is completely free to use and my only source of income are Adsense ads on the homepage and some sparse donations. Since May, when the site was featured on the front page of Reddit, my audience has increased with a steady rate, along with my ad revenue (almost $500 last month).<p>I don't really do anything maintenance-wise, except for answering questions from my users. I work on it from time to time, mainly adding new features or new country/regions maps, and I still enjoy it, as it was my first real programming project (I actually submitted it as a final project for EdX's CS50x course!).
About $300/mo on an app that provides real-time train tracking for Boston's commuter rail. Thankfully for me the MBTA is a mess, so each system meltdown (which happens about once a week) causes a spike in downloads.
I have made several small mobile apps. (<a href="http://anthonytietjen.blogspot.com/p/my-portfolio.html" rel="nofollow">http://anthonytietjen.blogspot.com/p/my-portfolio.html</a>) I charge for some of them, but my White Screen Flashlight has ads. (<a href="https://play.google.com/store/apps/details?id=com.anthonytietjen.whitescreenflashlight&hl=en" rel="nofollow">https://play.google.com/store/apps/details?id=com.anthonytie...</a>) If you are into programming, and are considering an app, make something super simple (like my Cost Per Sq Foot Calculator), and you might be surprised that people actually pay for it.
I run a few high frequency trading algorithms on Bitcoin and other cryptocurrencies. These are research-grade and not scalable (I already make 20-30% of trading volume on some exchanges), however, it still brings me around $200 per month.
I created <a href="http://www.ipaidthemost.com" rel="nofollow">http://www.ipaidthemost.com</a> over a year ago, and I can proudly say it's earned enough to buy a couple coffees. Well, if you ignore hosting. And the few times I dropped $50 onto it to try to advertise it.<p>It's odd. Most people who see it think it's clever and neat, and a few will buy, but when advertised, people bounce right off.
What do you think about <a href="http://sidekiq.org" rel="nofollow">http://sidekiq.org</a> gem approach where you have free open source tool and paid pro version.
I did similar thing with my open source gem knapsack for test suite parallelisation in ruby. I run pro version at <a href="https://knapsackpro.com" rel="nofollow">https://knapsackpro.com</a>
I wrote a book to help boostrapped startups choose the best hosting solution:<p><a href="https://www.hostingforappdevelopers.com/" rel="nofollow">https://www.hostingforappdevelopers.com/</a><p>Promoting the book has been the major issue for me, which is probably why it hasn't sold as much as I would have wanted.
I'm invested in forex (foreign currency trading). There are 3 buckets I'm in:<p>- $3500 deposited, run since Jun 3 (~5 months), current balance is $5200 (48% total profit, 8%/mo).<p>- $5000 deposited, run since Jun 28 (~4 months), current balance is $4590 (8% total loss, ~-2%/mo).<p>- $3000 deposited, run since Sep 2 (~2 months), current balance is $3218 (7% total profit, ~3.5%/mo).<p>It's certainly not for everyone but it's an amusing hobby. I've made a net profit so far so I'm happy.<p>I came to this after stocks as the research I'd found seemed to show that foreign currency fluctuations were significantly easier to predict (and profit from).
I run BitPixels (<a href="http://www.bitpixels.com" rel="nofollow">http://www.bitpixels.com</a>) that provides automated website thumbnails. I purchased Bitpixels from another HN member a few years ago and have continued to build and market it.<p>BitPixels currently makes ~$1k/month which is enough to cover the App Engine and DigitalOcean bills plus a bit extra. I'm working to find 1-2 more marketing channels that can drive sustainable growth.
I created <a href="http://convertcsv.com" rel="nofollow">http://convertcsv.com</a> and make about $750 a month off google ads. I also have one affiliate link but it isn't producing much. I spend a few hours a week answering emails, and another 2-10 hours a month working on enhancements. As a developer I work with data a lot, and noticed the lack of tools for converting delimited data - so I created my own tools online.
I make about 30 bucks per months on a single ad on my jquery plugin docsite[1].<p>I lose about 25 bucks per months on website for artists that I built over the course of a few years in my spare time[2]<p>[1]<a href="http://mkoryak.github.io/floatThead/" rel="nofollow">http://mkoryak.github.io/floatThead/</a>
[2]<a href="http://exhibitionnest.com" rel="nofollow">http://exhibitionnest.com</a>
I do peer to peer lending on an internet forum, VAs handle most of the work, ~$1k/mo passive, ~$3k/mo when active (but it's been passive for the past several months). I can try to answer what I can, but I can't divulge much more because it's not at all a defensible revenue model, and anyone with access to capital can do it.
I do run <a href="http://notationtraining.com" rel="nofollow">http://notationtraining.com</a> not the biggest source of money (~ 200 USD/month), but it keep earning money for six years in row, so I am happy about it.<p>Other then that: rental property, p2p loans portfolio (~ 6% pa) and small stock portfolio (around 5% pa).
Target retirement date funds, a handful of individual stocks for entertainment purposes. I also have dabbled with Lending Club (annualized ROI went from 15% to less than 5% recently) and the money saved on interest in paying back my student loans early.
I launched <a href="https://askdns.com" rel="nofollow">https://askdns.com</a> a few months back and making around ~AU$75/mo just from Adsense. There are around ~3M links in G now so the traffic coming in is slowly increasing.
I've been developing a tool that lets you create your own HackerNews. Then it grew to a SaaS that lets you create, manage and grow an online community.<p><a href="http://www.hellobox.co" rel="nofollow">http://www.hellobox.co</a>
3-4k per month. I own a rental property doing nightly rentals. I've automated all of the notifications, door code programming, arranging cleaning, etc.
absolutely nothing. Turns out its pretty hard to monetize open source developer tools. Really wish there was other stuff I enjoyed working on in my free time.<p>If anyone wants to start paying me for the JsFormat sublime plugin, let me know, I'll gladly take your money.