Why do people need to pay for porn in this day & age. It's 2015 not the mid 90's or early 00's. All you have to do is search on google for free porn. Unless people want some sort of specific porn that has to be paid for, I don't know, I'm not exactly an expert.

In my opinion not many people are going to pay for something you can get free online. Some escort agencies (hookers) accept bitcoin now though, now that kind of service you can't get for free so people will be willing to pay for that, the anonymity would be perfect.