The alternative, which airlines have been taking a good look at, is having no refund, no exchange, restricted change tickets. Those would allow airlines to be less concerned about no-shows. However, B6 is looking at backing away from that policy because it discourages business travelers.

Hubbed airlines also have a bunch of no-shows due to mis-connects so that will not help them much either. Airlines perform detailed statistical analysis on the loads and balance the costs of VDB, IDB and unsold seats and come up with an estimate of how many no-shows they expect on a specific flight on a specific day. If they expect a lot of vacation passengers, they seem to reduce the overbooking because vacation passengers usually show up. It is business passengers that are most likely to be no-shows.