Another well-written, sensible, and amusing article. Thank you, Amanda. I'd simply add that although it may be fashionable to do so, it is extremely unwise to ignore the effects of evolution. As E.O. Wilson (who, alas, died this week) pointed out and as countless studies have since proven beyond any doubt, our behaviors are as hardwired by nature as those of any other semi-intelligent species.
Thus, when we're considering the typical heterosexual date, the man has already evaluated the woman as "mate worthy" (or at least "mating worthy...") and now the woman has to evaluate the man as a potential provider. Paying for dinner is merely one gesture that enables her to calibrate his utility. Of course, neither of them are likely to be consciously aware of any of this, but then again most animals are unaware of their behavioral hardwiring - just ask any passing ant, rodent, or politician.