"In the eyes of many consumers the pricing issues surrounding supermarket "loyalty" card programs can be summed up in one simple concept: those who don't have a card pay more at the register. The stores portray it in a similar manner, but call it "rewarding loyal customers" with lower prices. But few things in life are truly simple, and supermarket cards are no different."

CASPIAN Consumers Against Supermarket Privacy Invasion And Numbering