Because physical attractiveness sells.
Does this surprise anyone?
It has to do with the halo effect if you want to know.
And for this same reason, I can make your wine taste good or bad.
I remember going to car show in Dallas my junior year of during high school. It must have been 1998. And do you know who they get to sell and talk about cars at car shows?
Beautiful young women.
It is hardly any wonder, then, that the halo of physical attractiveness is regularly exploited by compliance professionals. Because we like attractive people and because we tend to comply with those we like, it makes sense that sales training programs include grooming hints, that fashionable clothiers select their floor staffs from among the good-looking candidates, and that con men are handsome and con women pretty.
-Robert Cialdini, Influence