I think nostr will benefit greatly by using the stacker news model of "pay-to-do", you don's suscribe to a server but leverage the micro tx hability of LN to pay per note, pay per reaction.
I think that the Zapp will kill the "like" buttom, so having it now could be an example of skeumorphism.

In a more sophisticated approach we might want to think about where a relay operator expends the most and monetize in the bases of that. Is it bandwith? is ti storage? a combination of both?