http://online.wsj.com/article/SB10001424052748704463804576291181510459902.html?m od=googlenews_wsj
"Women account for only one out of 50 purchases of porn-site subscriptions, but they make nine out of 10 purchases of romance novels. (In fact, the main billing company for porn sites flags female names as potential fraud, since so many of these charges result in an angry wife or mother demanding a refund for the misuse of her card.) In 2008, 74.8 million people read an English-language romance novel?close to the number of men who visited online pornography sites that year in the U.S. and Canada."
So they don't buy. And men want 2 minute clips - the clip length on the tubes; pay sites thinking "20 minutes is a value add" perhaps aren't correct.