Paywall for exclusive or premium additional content is fine. But that requires the creator to establish themselves as a known commodity. And free-to-user content should not be abandoned because growing a new audience is always necessary.
That said, it is a challenge to create enough content that it justifies and maintains a paying audience. I never produced enough content with the podcast at a frequency that I felt justified having exclusive content. It didn’t seem honest to ask for someone to trust that I had more in store for them than I could offer on the regular podcast feed.
Still, while V4V didn’t produce riches, those times when I would get a random payment from a listener felt like someone dropping treasure in my hand. It was awesome to think that someone found my show valuable enough to take the time to toss me a few bob. Meant the world and was much more rewarding than running ads or sneaking behind a paywall.
But, any model is a good model if your audience agrees with you. On NOSTR, people understand that value of patronage and finding value in the efforts of others. I think this is a perfect place for v4v.