http://redtape.msnbc.msn.com/_news/2012/02/10/10366774-airlines-secretly-cash-in-on-unused-tickets With so much talk about airline fees lately, you might overlook perhaps the largest source of ancillary revenue for the industry — and a big headache for you — that lets airlines make money for nothing. A lot of it. If you've ever been on a "full" flight that was full of empty seats, perhaps you've wondered: What happens to the paid fares when passengers don't show up for flights? The airlines keep much of the money, of course. No-show fliers get vouchers for the unused value of their tickets good for a year from booking, but stiff change fees often eat heavily into that value. And much like unused gift cards, their value disappears into thin air when not used by a strict deadline.