At least for porn lover, it will give them more option for their payement method to buy some videos.
IMO, using bitcoin as payment method is far, besides fast transaction , it also anonymous. That's what they (I) looking for
you need to work hard to make it really anonymous(but it would be hard for them to track you back too), but still it give more confidence for those who want some privacy, insted of passing through all the hassle of a credit/debit cards
like satoshi said, it's good to use bitcoin for porn, if you do not want your wife , to discover it