I’ll just copy a previous reply:
the ads would ideally be limited to banners and gifs in the same style as these, with each user choosing whose ads they wish to host
no revenue or popularity (these are only for personal websites) would (hopefully) prevent users from hosting invasive ads. quite a few personal websites have banners linking to others, so this would be a more simpler approach
(although in principle, a whole project dedicated to automate this doesn’t sound good)>
these simple type of ads used in the early internet was exactly the idea I was going for, having little involved to breach privacy or be used as an attack vector. more individual user ads was also what I was imagining, and looking at them, they are quite funny too