I did the same exact evaluation yesterday on FAP.
CBS reported $97Billion several years ago, it's probably $100B now at least. Ultra4K video is very enticing to pull users from free tubes into paying, and being able to pay securely and anonymously is going to lead to an explosion of small pay sites that many are probably not comfortable giving credit card info to. The porn industry has driven technology for decades- it was the reason VHS beat out the superior Betamax format in the 1980s among other contributions.
There are however many competitors; the FAP team seems to be more aggressive than most, doesn't seem to be the best name though. Research them all and let me know which you think are best:
https://cryptoslate.com/category/cryptos/adult/