Airlines often overbook flights as they want to minimize seat wastage and prevent revenue loss caused by no-shows, last-minute cancellations and flight delays. It improves the odds of airlines achieving 100% flight capacity, as empty seats mean less money. Flights can also be overbooked for operational reasons, such as an aircraft change or if seats are inoperable. Airlines often overbook flights based on historical no-show data, according to Travel + Leisure.