Airlines overbook their flights as a matter of necessity. In the current economic environment, they simply cannot afford to take off with empty seats. When every ticketed passenger shows up at the gate, someone must be "bumped" from the flight. In this situation, airline employees must ask for volunteers before they deny seating to a ticketed passenger. The reward for volunteering can be vouchers for free travel in the future. Find out more about how
being bumped from a flight voluntarily can reward you for flexible travel plans.