I generally don't see a girl again unless there's some seriously heavy petting on the first date and sex on the second date. Of course I prefer there to be sex on the first date.
If a girl explicitly tells me she's not going to sleep with me until [whenever], I usually end the date quick and find another girl!
I've been doing internet dating for about 7 years. Dated lots of girls, had some long term relationships, some multiple-LTRs. About half the girls I've gone out with screw on the first date, a quarter on the 2nd or 3rd date, and the last quarter make it clear that it's not going to happen any time soon /or/ there's no connection, and thus there are no further dates.
IMHO if she's interested enough to go out with me after a few chats and maybe a talk on the phone and seeing my pics, she's interested enough to screw me. I know most people won't agree with that, but that's my experience. I put up accurate pics, make it clear what I'm looking for, and have a fairly charming personality.
The reason I say that is, if she holds out, it's a power-play on her part that I want no part of. That is, she's saying, "*I* control the sex, honey. We'll do it when *I* want to, not when you want to." And there's no way I want some woman dictating my sex life. So I always multi-date and cut 'em loose on the first or second date if it looks like they're going to play hard to get.
In general that also means that I date women who are more into me than I am into them. No 10s for me

BUT, no getting the run-around either. Right to the point. I don't date women who think they're going to be the shot-caller in the relationship, and I can smell those types from a mile away at this point.