In an interesting move United Airlines has opted to utilize Microsoft's Zune to entertain flyers. Up until the end of May the air carrier used Sirius XM. The contract with satellite radio was not renewed.
Zune, which has had trouble gaining penetration into the market, is likely using the deal to gain exposure much like satellite radio did a few years back.
The deals with airlines do expose travelers to services, but the effectiveness of such deals is difficult to measure. Sirius XM is still the music entertainment provider on Jet Blue.