My side project https://playtoearn.one/ is not making $500/month yet, but it's getting there: a tiny bit more than $400 for this month
It's getting around 250-300 visitors a day, and in a high paying niche
I started using "classic" ads - which were/are making next to nothing - but just signed a deal with a direct client for 400$ for 3 weeks of displaying his game on the site, on the top banner
There are so many play-to-earn games popping up at the same time that projects are fighting for visibility, which playtoearn.one can bring
So now, I've hired a designer to make a great looking UI and I'm getting motivated to turn this side project into something more than this
- The first one was a trivia game made with javascript (Vue.js), it was a hit on Reddit around a month after launch and became the top post on a 900k subs subreddit, I was contacted soon after through reddit mail
- The other one was sold on flippa, so they took a large cut of the sale
It doesn't exactly qualify as a one-man business, but I'm running a few side projects bringing around $500/month:
- https://batgrowth.com: A website monitoring the growth of The Brave browser / Basic Attention Token, in terms of publishers adoption (Fun fact: Wikipedia founder, Larry Sanger, tweeted about the site)
I've built many more side projects, most were earning $0/month after a few months, but I've also sold 2 side projects, so overall it's worth the effort