Ask HN: What is your best side project / passive income in 2015?

Improvely (https://www.improvely.com) and W3Counter (https://www.w3counter.com) both started as tools for my own use, and are now the passive income I live on. They're both analytics tools -- one's geared towards professionals, and the other to hobbyists. Improvely is purely paid subscriptions, while W3Counter is freemium with some ad revenue.

In the 2012 thread, I had just launched Improvely.

In the 2013 thread, I had hit $10K/month in recurring revenue.

In the 2014 thread, revenue had doubled to around $20K/mo.

Since then, revenue has doubled again, to around $40K/mo.

I still work alone. I took all of August off to visit my girlfriend's extended family in another state and then a beach vacation when we got back. Other than keeping my Surface tablet in my cabin/room in case something were to break that health checks and autoscaling can't fix, and answering a couple customer e-mails before bed each night, everything ran itself just fine.

Another side project that's weirdly taken off is "Improved Contact Form". It's a little one-click-install app for Shopify stores that I threw together for a relative. It adds one of those floating "Contact Us" buttons to each page, that pops up a contact form, along with a dedicated contact page. When someone submits either form, the store owner gets the mail along with a list of all the pages the customer viewed before contacting them and the customer's location (geoip lookup).

I threw it up on their app directory for free, and a year later, I host the contact forms on 10% of their stores, which is ~17K companies or so. I'm going to need to leverage that into something eventually. Maybe a whole suite of one-click-install widgets for shops, like a SumoMe for ecommerce.

I wrote and published a novel about a game played in virtual reality in the year 2020 (http://www.amazon.com/gp/product/B00ZFF6NVK). It came out three weeks ago and has been providing "holiday money" rather than just "beer money" so far.

My grand vision is to create the game in the book for real, to launch in 2020, just like in the book (more info here: solarversia.com/about/). It's had a great reception so far (I've targeted Ready Player One fans) and I'm in the process of bringing on non-execs to Spiralwerks, the company behind the game (which features heavily in the book), and also talking to agents who might want to represent me for a traditional publishing deal. Meeting my first VC next week.

If it wasn't obvious, I'm hoping for a big wave of publicity when Oculus / Morpheus / HTC Vive et al launch next year.

Oh yeah, my London Live interview where I discuss the big vision: https://www.youtube.com/watch?v=0bo0u3C5D-Y

If you know anyone in VR / publishing, I'd love an intro.... :-)

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I released a book teaching beginner Django web app development: http://hellowebapp.com

Sure, it was quite a bit of work beforehand, but I've made around $25,000 from it so far, around $13,000 if you don't count the Kickstarter campaign.

The first book working so well is one of the reasons why I'm writing a followup book (which is fundraising on Kickstarter now: https://www.kickstarter.com/projects/1868398473/hello-web-app-intermediate-concepts)

FYI: The best thing I did when releasing a book was to a have a super-tier with screencasts and videos. That one tier provides ~60% of the revenue from the sales of the book.

I self-published a guide that helps junior developers dramatically improve their chances of getting hired at startups: https://kokev.in/hired-fast

I'm glad I didn't do it solely for the money, because I think revenues so far works out to something around minimum wage. However, it was a pretty satisfying challenge and I enjoyed every minute of it. I've gotten some great feedback from people who have landed some great jobs, so it provides a sense of fulfillment.

Like many others, I relied a lot on Nathan Barry's Authority (http://nathanbarry.com/authority) to write this ebook, which I'd recommend if you're looking to do the same.