“Ralph's (and virtually all other) grocery stores provide customers with "frequent-buyer" or "Club member" cards that entitle holders (Group B) discounts not provided customers without cards (Group A), on the argument that people who tend to buy frequently (and/or buy in large quantities) have good reason to comparison shop and to obtain the frequent-buyer cards: they can prorate their search costs over a large number of purchases.11”
―
Richard B. McKenzie,
Why Popcorn Costs So Much at the Movies: And Other Pricing Puzzles
