The challenge is that there won't be any transparency with this sort of thing. Prices for flights are so variable that you'll probably never know if it is cheap

The challenge is that there won't be any transparency with this sort of thing. Prices for flights are so variable that you'll probably never know if it is cheaper due to the advertisement, or because of other variables. My main issue with advertising driven models is that the company will respond to the needs of who pays them, advertisers, and not who actually uses the service. Want to juice profits? Just sell more advertising slots, make them more intrusive, etc. Delivering quality service to customers becomes a cost burden rather than a way to gain more customers.