I don't see any reason why men should pay.
And anyone who does believes that they have to buy their lady's approval. Sorry but if i wanted that i'll go visit a prostitute.
It's a tradition that stems from a time (the 50's and before) when men made money and women often didn't, so there it made sense. Nowadays, men and women pretty much have equal opportunities and financial strengths, so it makes absolutely no sense for us to pay. Of course, there are exceptions, for instance when you surprise her and take her out for dinner or whatever. But when it's a date, why should the man pay? Just because she has boobs? Screw that. I always split the bill (not up to the cent, but just an easy amount that's sort of fair), and when you're having fun, women are more than happy to do so.
I don't like the idea of trading money for her liking me. I want her to fall for me, not for my wallet. Use your brain, men. Don't buy (literally) into traditions that are not applicable to current society anymore.