Overbooking = more profit, but often = unhappy customers. Airlines use statistics to avoid overbooking, resulting in 50k people getting bumped off flights annually. Airlines use data to predict the number of passengers boarding a flight.

Overbooking is frequently criticized as unethical because it involves an airline selling the same physical inventory—a seat—to multiple parties, knowingly creating a situation where they may be unable to fulfill their contractual obligation to a paying customer. From a consumer rights perspective, it is seen as a deceptive trade practice that prioritizes corporate revenue optimization over human reliability. When a passenger is "bumped" (involuntary denied boarding), it causes significant emotional distress, missed weddings, funerals, or business meetings that monetary compensation cannot always rectify. Ethically, it violates the principle of "good faith" in a contract, as the passenger has often made non-refundable hotel and tour arrangements based on the airline's promise of transport. While airlines argue that "no-shows" waste fuel and seats, critics argue that the burden of this risk should fall on the corporation rather than the individual traveler, who is essentially being used as a hedge for the airline's profit margins.