A fee comes with the problem that content can now be censored by refusing to sign an event saying they paid the fee.
Discussion
Why do you need to sign an event saying paid?
You cannot enforce the fee otherwise
how about lnurl-withdraw or cashu sent with the video?
Cashu may as well be a signed event, like zaps.
LNURLW is not proof (it is an offer to pay, not proof of payment)
Isnt a directly taken "offer to pay" a proof? What do I dont see in the context?
Or you mean you need the proof for "accounting" purposes?