Ask HN: Those with successful side projects that required minimal marketing

Common advice I've heard is you're gonna need a lot more than a single release to Product Hunt to market your product. For those that have had to do minimal marketing (people shared it with minimal prompting, product grew on its own, etc), what's your story and if you're comfortable sharing numbers, how much does your side project make?

Honestly, this sounds like a developer's dream, so would be very interested in hearing at least one story