It's the busiest travel time of the year and if you are flying you face the possibility of being bumped from your flight. Airlines want to make sure they make money. After all it is a business and to be sure that they don't lose money they may sometimes overbook a flight.
What the airlines do is surmise how many people will cancel or be a no-show. How can you avoid getting bumped?
Make sure that you get an advanced seat assignment. Even if you can't stand being in an aisle seat and it's the last one available by the restroom, take the seat. Airlines will usually bump you only if you are late and your seat has been released.
Which means get to the airport early. Some airlines reserve some of their seats so people can check in at the airport. But with most things done online the number of seats are few and far between -- or they are literally between meaning you get stuck in the middle of a mother and her kids who have runny noses and can't sit still for a 5-hour flight. You are now the inflight entertainment.
While your ticket may say "confirmed," if you do not have a seat assignment, you will be treated by the airline as a "standby" customer.
Of course the airlines also have something called volunteer bumping -- when airline employees will look for volunteers when it appears that the flight has been oversold. If you're not in a rush to arrive at your next destination, you can give your reservation back to the airline in exchange for compensation and a later flight.
Brett Snyder, who runs air travel assistance service Cranky Flier says voluntary bumping is "generally really good for everybody involved."
"Airlines know there will be no-shows, by selling more seats they're able to keep fares lower because otherwise they wouldn't be able to sell those extra seats at higher fares. Then for all the people that get bumped voluntarily, they get freebies," he said.
The U.S. Department of Transportation (DOT) requires each airline to give all passengers who are bumped involuntarily a written statement describing their rights and explaining how the carrier decides who gets on an oversold flight and who doesn't. The airlines will generally compensate you if they have to bump you from a flight. The amount depends on the price of their ticket and the length of the delay.
You can view the DOT's rules about bumping here.