Customer loyalty cards are typically used by businesses to reward their customers for repeat purchases. When a customer makes a purchase, they can present the loyalty card to the cashier. The cashier will scan it and the customer will earn points or rewards for that purchase. Once the customer accumulates a certain number of points, they may be eligible for discounts or other rewards from the business. Loyalty cards may also be used to track customer purchases, allowing businesses to tailor offers to individual customers.