People lose excitement about products as more and more are “on sale” – perhaps why Woot.com is so popular (sells only one item at a time): “Tversky and the young Princeton psychologist Eldar Shafir asked experimental subjects how they would react to a desirable Sony appliance placed in a shopwindow, radically marked down. The offer met with predictable enthusiasm. When a second appliance, similarly marked down, was placed alongside the bargain Sony, enthusiasm