I built Premium Ghost Theme marketplace http://www.gtheme.io/ to sell premium ghost themes. I designed most of the themes because I have chicken and egg problem. Now I get about $100-$300/m revenue.
Most people still dont know what is Ghost https://ghost.org/ yet. It is CMS that like Wordpress, but built on NodeJS.
A ghost theme market place you say? I went to the site and sure enough, it's ghost themes. Premium ghost themes in fact. I still have no idea what the fuck ghost themes are though.
I would guess that not many are making a $1,000 a month on side projects. Most of my friends have side projects where they make $100-$300, but when they get to over $500 they consider making that the primary project.
Some games make that but you have to continue to update them or they loose their ability to continue to sell, so it's misleading when people say "I make $1500 a month from my games" they should also say "I spend a couple hours a week making sure they are updated to the new versions".
But you may already know that.
I will follow you're question to see if you get much response. I would love to be surprised!
I started with a free version that I posted on various freeware software sites and as many forums about laptops as I could find. I also watched referral URLs can tried to engage users. Eventually users started spreading the word themselves. I've tried AdWords a few times but the ROI hasn't been great.
Looking at the source, its an iframe for this site: //www.redditmedia.com/r/angularjs/comments/2f7ziz/i_quit_my_job_to_teach_you_how_to_launch_a_full/ckbhk0m?embed=true&context=0&depth=1&showedits=true&created=2015-05-04T04:25:24.511Z&showmore=false
I wrote a book about the Meteor JavaScript framework, which is available for free, but I also sell a video training series that's based on the book: http://meteortips.com
I (still) make >1000 on my watermarking windows program at www.watermark-image.com - yes an old skool installer that you dowbload :)
I am using the money to stairstep (as Rob Walling talks about) into the SaaS world with my sleep and happiness improving way to work called TimeBlock (http://timeblock.com)
It's a brilliant idea. Just curious but which data sources do you use?
Was diving into football analytics awhile back but was having trouble getting beyond the usual statistics (e.g. goals, wins, losses, games played, etc).
Most people still dont know what is Ghost https://ghost.org/ yet. It is CMS that like Wordpress, but built on NodeJS.
EDIT: Added what is Ghost