Think about the primal imperative of attracting a prospective mate. Many people are too shy (or civilized, maybe) to just grab a breeder and go, so we humans announce our availability to the opposite sex more or less silently.
Think about all the attention females place on their man-hunting clothes and face paint. And all the time and energy that men use to find just the right curl of our lips, tilt of our hips and pheromone-piquing allure of our scent (I just read this--and I swear I'm not making it up: "…the middle notes of clover and violet retrain the patchouli as Tunisian neroli bursts through this 18% cologne." And we call ourselves men?).