When you book a flight ticket, the last thing that you'd expect is the flight to be overbooked. But this is what happened aboard the United Flight 3411 which was due to leave from Chicago O'hare to Louisville Airport or Sunday 9th April, forcing one passenger off the flight in a violent way. As it happens, airlines do routinely sell more seats than they have.
Why do airlines oversell? They do so because they expect a certain percentage of passengers to not show up, which airlines refer to as the 'No Show Rate'. This is calculated from past data and is used as a prediction tool and allows the airline to determine how many tickets to sell to make a profit. Some airlines tend to overbook more often than others. The chart below explains in great detail how to avoid being bumped from a flight.
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