Paris Hilton uses fashion to test if someone is a real friend or not. Of course she does. That's what shallow bitches do. From Hilton's interview with Fabulous Mag (UK):
FABULOUS MAG: Halitosis or hideous dress sense are a given, but what other qualities would make you rule out a girl as your BBF?
PARIS HILTON: I don't like it when people are liars or users - girls who are just trying to be my friend for the wrong reasons. I've had a lot of people in my past who were friends with me just to get publicity. When I was young, my mom or sister used to have to point out if someone was using me to make a name for themselves - you know, linking arms with me on the red carpet and trying to get in every picture. But now I can see for myself when someone is just hungry for attention.
I have this great test to see if a girl's a real friend. When we're shopping I'll pick out an outfit that I know looks hot and one that is awful. If my friend says the bad one looks good, I know she's not a good friend.