Can't help you online, but a line that one of our scouts uses that apparently actually works quite well at clubs is "If you fuck half as good as you dance, you should consider porn. Have you ever thought about it?"

I just about fell off my chair when he told me, but apparently it disarms people and complements them, and gets them willing to talk. If you could find something of a similar disarming thing to do online, that might be a way to go.