As if SWA is the only airline to overbook.
I've had overbookings on other airlines too. Once on Frontier, I saw them actually choose a passenger to bump (he was sitting close to me) in order to accomodate one of their Premier Frequent Fliers who arrived at the gate late and asked to be on the flight (I heard him talk about it when he sat down about how thankful he was to catch this flight). Talk about poor customer service for the poor schmuck that got involuntarily bumped after having already sat down. I've also seen United ask for volunteers to be moved to later flights.
ITA...on our many flights with SWA we've heard them asking for volunteers to be bumped a few times. On our last flight, they asked for volunteers and we were sitting close to the rear of the plane. The lady behind us was actually upset that she was too late to take them up on their offer.
We're not frequent fliers who get all of the privileges of free checked bags, extra legroom, etc. on the other airlines, so we choose SWA. We like the lower fares, its free bag policy, the fact that they do not charge a fee to have to change your flights and that that they give you "credit" if you find the tickets at a lower price and rebook them at that price. We've also had great luck with SWA being on-time and not moving flights around.