If you do it right, bumping's not bad. The odds increase during peak travel periods and when weather conditions force cancellations and airlines need to accommodate more passengers on fewer flights.
Some people love to be bumped.
It's their favorite route to free travel. If this is your strategy, check in for your flight as early as possible and ask if the flight is oversold or needs to accommodate extra passengers. State your willingness to be bumped in return for adequate compensation. Most airlines will ask you to fill out a form to that effect. Take a good look at the terms of the compensation offered.