Why does sex always sell?

As I've been hunting down the best post-holiday sales, I've encountered the same old slogan: sex sells. For example, there's a line of makeup called NARS Orgasm. There's a set of blushes that will apparently give a woman the "effect of an ultimate super, uh hum, afterglow." There is something about naming a blush "G spot" and "super orgasm" that makes me uncomfortable. Why is that the only way to sell any product is to oversexualize it? I see a clear link between wearing this makeup and looking sexy for a man. It also bothers me that the point of this makeup is to make a woman look like she has just had an orgasm as if a woman's appearance is constantly on display for others. 


Yet, I can see the empowering message in this makeup. When I get dressed up or wear makeup, I like to look nice for myself. I just wonder why makeup must be associated with transforming one's physical body and therefore, inner feelings about herself. Is there a way for makeup to have a fun and useful function without the instant gratification that it makes a woman more "beautiful" than another, and therefore, more attractive to a romantic interest?