Markets is good one! Integrated P2P inside the clients or P2P exchange, Coinjoin, where you charge fees but then you gotta watch for the friendly jurisdictions that you will not end up like samurai devs or Ross Ulbricht
Discussion
P2P tends not to work very well, and is going on (and mainly failing) in a few different places. Coinjoin is a red flag for the feds, so devs dont really want to risk it. Maybe some will, tho. Fees wont add up to much I expect, and mixing can be done in many other places. I think AI integration will be a good match for nostr. Combine that with games too. Lots of viral paths for social games.
There are definitely good ideas to be explored but not any time soon! Devs are comfortably are being dependent on none profit orgs