I've tried adult friend finder, lavalife, and ashley madison. Waste of time and money! The only one I've had luck with was lavalife - but again it was with woman looking for a "committed relationship". But if your looking for a no strings attached relationship I think you would be hard pressed 20:1 guy girl ratio...
Got a couple of hits on Ashley Madison, but certainly nothing to write home about. My theory is that they actually employ people just to send winks, etcs, to make you pay for credits. Just a thought.