cloud fodder on Nostr: Right, it seemed that everyone decided paying per-month was the way to go for spam ...

Right, it seemed that everyone decided paying per-month was the way to go for spam solution (wasn't considering pay per message i agree that would limit conversation too much). If you go on nostr watch it literally says my relay has no 'spam protection' because it's free. lol. Basically, I do get nervous that when spammers decide to attack, it's very easy for them. I don't have any plans to convert to paid for my relay, but for building other relays, I've been thinking about it a lot. Reply advertisements would be far too annoying I think, because they ruin a conversation like these reply-bots already do. One possibility could be like a payback, you pay, it goes into the relay holdings, if you aren't identified as a spammer you get it back at the end of the month? Another would be to have a database of people that have zapped, and use that as a list of people that are allowed to post. (except zaps are not verifiable by a 3rd party, but it would be one more hoop for a spammer to jump through).