I think it is odd that an advertising relay hasn't been made. (I know there aren't many of us here that might be a factor). I think it could actually be a selling point for some people, especially people arriving on zero sats. I know it's not for everybody and most people here are probably quite wealthy and on above average incomes,.so it wouldn't appeal to them. But I think it could function like how Brave Rewards should be.
Obviously it would need some mechanisms so it wasn't abused with someone spinning up thousands of npubs and claiming advertising rewards. (Maybe PoW and caltchas - no idea).
(Anyway if anyone wants to go into business with me lol...)