Um, Twisty's has a rating system and I believe the surfers vote for Treat of the Year? I figure they didn't always have their cms coded with that from the beginning, but that now gives them the data they need.
How do you think they decided which girls to pick for solo sites?? The popular ones.
and hey, I'm female... if *I* can sell porn to men as a straight female, anyone can figure it out. Stats ftw