Clothing companies contact the publicists and wardrobe departments of production companies and say "I will give you this dress for free if you mention that it is my dress on air".
The publicist or wardrobe department tells the celebrity to put this on...
The celebrity wears the dress on the red carpet or on a show or in a movie and the clothing company or designer gets their name mentioned.
The rest of the world goes "OMFG! She wore that! NOW I NEED TO WEAR THAT!"
It is a rare thing that a celebrity wears something that becomes a trend that they chose to wear themselves.
Celebs hire people to organize their wordrobe for them...
Celebs don't have time to do it themselves...
Celebs that dress themselves get caught on camera wearing sweat pants, a half shirt, and hooker pumps...
It is all a process of "Getting my name out there" and associated with a celeb to push the brand... It has very little to do with what the celeb does themselves.
The only real acception to the rule is Oprah... This woman is a pimp for whatever it is she likes...
$50.00 pair of plastic flip flops? Say the name on air and suddenly every braindead, brainwashed house wife on earth HAS TO HAVE THEM!
Cheese cake that sells for $100.00 for an 8 inch round that is mailed to you in a wooden box? She mentions how much she loves it and the company is almost put out of business with the wave of orders...
The cult of Oprah is one of the few things that is actually pushed by the celeb because she likes it and not because she gets free shwag if she says their name on air. She is WAY too rich to care about free shwag.
