A retail establishment or a retail group may issue a loyalty card to a consumer who can then use it as a form of identification when dealing with that retailer. By presenting the card, the purchaser is typically entitled to either a discount on the current purchase, or an allotment of points that can be used for future purchases. Hence, the card is the visible means of implementing a type of what economists call a two-part tariff.

The card issuer requests or requires customers seeking the issuance of a loyalty card to provide a usually minimal amount of identifying or demographic data, such as name and address. Application forms usually entail agreements by the store concerning customer privacy, typically non-disclosure (by the store) of non-aggregate data about customers. The store — one might expect — uses aggregate data internally (and sometimes externally) as part of its marketing research.

Where a customer has provided sufficient identifying information, the loyalty card may also be used to access such information to expedite verification during receipt of cheques or dispensing of medical prescription preparations, or for other membership privileges (e.g., access to a club lounge in airports, using a frequent flyer card).