I just know that some traffic providers won't sell to xxx sites. Some will not provide traffic for pharmacy sites either.
I also know that many normal sites won't want to link to you for fear of being penalized by google. Your a "bad friend" to be linking too.
I have seen some link building for porn sites done in forums where people have asked stuff like "what's the best porn site" these are usually requests for free porn but you might have some samples that are free or something. To get people to your site, than you can draw them in
The best porn site coverstation I saw on Reddit
Places like Empornium have forums too. Everyone there wants free porn but you might be able to get a link out of them. If you could find a way to stop people from downloading it and sharing it for free you might be alright. They are probably never going to pay but maybe you can get them to fill out a simple CPA offer and then unlock your content. As long as they know up front that they are going to have to spend 3 minutes filling out a political survey or something. You would need gather information for the CPA offer, not send customers, or the business that puts out the offer will cancel you once they find out none of your visitors do anything for them.
You would probably need a way to hide where your traffic comes from too.
I have seen some Clips4sale work, it is good. You just gotta keep the free lunch crowd from eating you out of house and home.
People love porn, but they don't want to pay for it, soon there will be no money to pay actresses and actors (or access providers) and there goes the porn they love.