At the Broadway/Lafayette station, Diesel jeans tells passersby to "BE STUPID."
I agree with You Bent My Wookie, who has more images of the ads, and says this is "the most straight forward and idiotic marketing campaign yet...you’ve got to be stupid to want to pay $290 for a pair of jeans."
Someone else agrees, too--they responded to "Be Stupid" by sticking an Andre Breton quote on the billboard.
It says: "The mere word freedom is the only one that still excites me. I deem it capable of indefinitely sustaining the old human fanaticism. It doubtless satisfies my only legitimate aspiration. Among all the many misfortunes to which we are heir, it is only fair to admit that we are allowed the greatest degree of freedom of thought. It is up to us not to misuse it. To reduce the imagination to a state of slavery—even though it would mean the elimination of what is commonly called happiness—is to betray all sense of absolute justice within oneself."
In others words: DON'T BE STUPID.