It's not the girl's fault tho. Cause 95% of the dudes out there WILL in fact buy her a drink when she acts. Shit, if I had that power I would sure as shit use it constantly, lol. I don't blame the chicks.
But, it actually sets up quite nicely for the few high value dudes who actually look at the chick and laugh at them. I was at a club in NYC a while ago and it happened to be 18+ that night
Anyway, those of us over 21 had bracelets so we could buy booze. So, a group of under 21 girls came over to me and my buddy and did the flirt thing then jumped in with "Will you guys buy us drinks?". So, I made them each tell me a joke or an entertaining story. It was awesome to watch them rack their brains to try and come up with something good for me - even when they could have said "screw off" and gotten some other sucker to buy em drinks. They liked it. We chilled with them most of the night and had a great time together after that.
Moral of the story - they were just doing what they have been socially trained to do. And when I threw em a curveball, it actually acted as a qualifier. A test of sorts. They passed and we all immediately had a little more respect for each other. And then we all had a ton of fun.