Checkout charity is a phenomenon whereby frontline employees (or self-service technologies) solicit charitable donations from customers during the payment process. Despite its growing ubiquity, little is known about this salient aspect of the service experience. The present research examines checkout charity in the context of fast-food restaurants and finds that, when customers donate, they experience a “warm glow” that mediates a relationship between donating and store repatronage. Study 1 utilizes three scenario-based experiments to explore the phenomenon across different charities and different participant populations using both self-selection and random assignment designs. Study 2 replicates with a field study. Study 3 examines national store–level sales data from a fast-food chain and finds that checkout fund-raising, as a percentage of sales, predicts store revenue—a finding consistent with results of Studies 1 and 2. Managers often infer, quite correctly, that many consumers do not like being asked to donate. Paradoxically, our results suggest this ostensibly negative experience can increase service repatronage. For academics, these results add to a growing body of literature refuting the notion that small prosocial acts affect behavior by altering an individual’s self-concept.