I think that to really understand the whole travel bank thing, one needs to review what happened in MOB (Mobile, AL).
Mobile is 302 NM from ATL, but had astronomical fares and spotty service to ATL, as Delta was the only game in town. AirTran started service to MOB, and Delta immediately matched the low fares. Mobilians were delighted at the sudden benevolance of Delta . . . fares cut in half, more service . . . . what's not to like?
Meanwhile, AirTran was finding it hard to fill up their airplanes. After all, at the same price, which would you have chosen- Delta, with frequent flyer points, nicer airplanes, more frequent service, or AIrTran, with ratty old DC9's, less frequent service, and a fledgling FF program?
AirTran, with low ridership, started warning Mobilians that if they didn;t use the service, they would pull out . . . to no avail. Eventually, they did just that. Delta raised their rates right back to where they had been previously, and the people of Mobile wandered around in a daze, wondering what had happened.
In the end, it was a losing propsition for both- Airtran had lost money on the experiment, and Mobile had lost the opportunity to have lower fares.
Since then, AirTran has learned to get the community involved, in the form of a ticket bank. If the people fail to utilize our service, the travel bank keeps us from losing money. It takes over half a million dollars to open a new station, so the advertising dollars helpd mitigate that cost. The business community has a stake in promoting the new service, and it lowers our exposure.
In the end, if these communities were being chargeD a fair price to begin with, they wouldn;t have a desire to bring us there in the first place.