Bitcoin can have many use cases like this one in the adult and porn industry, meeting and dating websites, etc. And I am sure it will have after the Ashley hack.
The question is, Will Bitcoin give them more anonymity? If the user go through a 3rd party payment processor, he is still doing the same thing he would have been doing, using a credit card for payment. Bitcoin is only pseudo-anonymous, if you use it in the correct manner.
It still gives you the better option, if you do some home work. ^hmf^
That's why you should mix your coins in order to gain even more anonymity. 100% anonymity isn't possible, but you can "clean" your coins and then spend them on whatever thing/service you want. I always mix my coins before sending them to my cold wallets and even before spending them.