Age and gender targeting
 

What targeting would it be good to use for pages / websites in pornstars niche. I guess I would select men only (based on some experience in this), but what age range would be the best for this?

Thanks.

Very few here will be able to answer this question, because most of them have no idea about marketing, but if you are using Google Analytics in any of your sites it may help you.

http://i.imgur.com/0smNpFf.png

On the left side there is this part called "audience" where you collect a bunch of information about your visitors, from sex, to age, language, geo location, etc... this information will help you to understand your visitor and buy advertising where they have a simmilar demographic audience, that is exactly what the tool is for.