Levi's hasn't been "the cool brand" in quite a while. Nobody sees someone else in LEvi's and thinks "man, I've got to get me a pair of those cool jeans." People buy Levi's because it's what they find comfortable, it's what they are used to.
Wearing it is endorsing it. That's all I'm saying. That's why they put the tag on it, so other see who's endorsing their brand.