Interesting... Yeah I didn't realize so many of these sites exist. Something seems to be preventing them (or especially one) to really gain prominence and name recognition.

My suspicion is that people contributing to open source don't really just contribute randomly. It is most likely that they use a library or repo and then they end up on the "issues" page because they had a problem themselves.

It's at this point where I would imagine one is most likely to convert into actually picking up an issue and when notice of a "bounty" might push someone over the fence (?)

Honestly, solving the problem is more of a push than any additional income. If there was a way to search for the bounty, maybe, but unless it's integrated into the project somehow, it's not worth searching out.

I keep telling myself this is something I'd enjoy doing - but then I do something to scratch my own itches instead and live without the bounty.