Western morality is trying to outlaw something that's been going on since the beginning of time (well, almost). Simple economics: Guys always want to get off (demand)-->There's a lot of money to be made in lending a "hand"
(supply).
By the way, I feel that we all "pay" for sex one way or another. Whether it's going to a massage parlor and handing over $100 or going to the store and buying your girlfriend an expensive present.
Then again, maybe I've just finally become too cynical!
(Seriously though, when you take a girl out on the town and blow through $400, what are your motivations? Be honest
)