John sells televisions at Best Buy (a local electronics store). He gets an extra commission if he sells the Best Buy brand, "Insignia." So, when he talks to customers, instead of comparing all of the brands the store carries, he tries to focus the customer in on just one or two other brands and compares those to the Insignia. In this way, he can limit the number of brands the customer considers. In thinking about your readings on consumer decision-making, this is an example of what concept?