If your travel plans are flexible take a later flight

Sometimes airlines do overbook their flights. You know, people sometimes don't show up for various reasons.

Since the airplanes can't take anyone standing up, the airlines will ask for volunteers to give up your seat. For this gesture of kindness, you will be rewarded with some kind of travel voucher for a future flight.

Some airlines will solicit you at their kiosks others at the gate. So if you can take a later flight, why not volunteer the next time you have the option.