The whole punting thing has changed over the last 10 years. More students are doing it simply to stay at Uni, pay bill etc and the younger ones I've seen said they enjoy sex and rather than have one night stands, prefer to be paid for having sex.
Some I have talked to also take the piss about guys cheating on their wives and getting the dirty things that they can't get from GF/wives, as one put it. A lot of the WG I've seen also have a life plan, punting to make money, then find a nice guy.
It's a sign of the times, and I'm sure if the laws were changed, google would be with first to put up an AW style marketplace!