MarkS: It won't work that way. I should probably write up how it will! First off, Aircell has committed to working with aggregators like iPass and Boingo. Frequent travelers will already have an account through work or personally with one of these services. They'll also be trying to work with all the cell carriers. And they'll work with the frequent flyer programs. It's unlikely unless you rarely travel that you'll wind up punching in a credit card number to use Aircell. If you're in the air 2 or more times a month, you'll have the means to avoid paying each time.

The airlines are definitely not going to subsidize this service except for their best flyers. The airlines are expecting to gain more passengers, but not much revenue, from this service, and they have no fat to give back at this point.