1. SnapShooter ($1k+/mo), a tool to create daily backups of DigitalOcean droplets:
" I tried sponsoring blog articles with a little bit of success." [2]
2. BugFender ($35k/mo), a log storage service for app devs:
"Here's what didn't work: sponsoring developer newsletters and podcasts" [3]
The reason for this (IMO) is that most products that advertise themselves (especially on dev blogs) are not unique/compelling enough. Why should you buy a sponsored app logger when you know 10 other look-alikes with 5 other friends using them? The fact that these guys managed to invest $6k and get $200k in return from sponsoring a blog just shows how unique/compelling/valuable their value prop. is. Good luck!
[1] https://firstpayingusers.com
[2] https://www.indiehackers.com/interview/how-starting-small-he...
[3] https://www.indiehackers.com/interview/turning-an-internal-c...