Sneaker Pimps (n):

1.A fence for stolen sneakers back in the late 80's and early 90's during the Nike craze. People would steal high dollar sneakers and sell them to a sneaker pimp who would then turn and make a profit off of them by selling them for less than the stores.

2.Although less believable, another definition was a group of people hired by the Beastie Boys to find vintage sneakers.