Promote a Forum/BBS site where users post their own home made photos and videos
http://www.nakedsurfers.net/vb/
cookies are valid for 7 days, it's enough for users to see that the free forums don't have much good porn (just softcore) and free users don't have many good features enabled, so they should join the paid forums
http://www.nakedsurfers.net/webmasters/
there you can signup for account with CCBILL
it really makes money. Just place a small link on the bottom of your sites and see how it works
thanks