Knowing What You Don't Like.
I heard it suggested that women like Sarah Jessica Parker in Sex & The City all the more because men cannot fathom why. I don't know if that's true or not but my immediate reaction was to suggest flippantly that it was a default position resulting from the fact that they didn't want to be identified via the other characters as primarily either overtly promiscuous, frigid or subservient.
Perhaps that's nonsense. I'm not a woman after all. But just as great marketing is all about removing the reasons not to buy your product/service, perhaps it's worth thinking how your product/service allows customers to defines themselves in terms of what they are not.