One could imagine penny-pinching airlines like Ryanair tearing out all their existing seats and replacing them with these, knowing that their clientele don't mind an hour or two of discomfort in return for getting to Ibiza or wherever for less than the train fare to the airport, though, as pointed out here, an entire jet full of these won't be possible for regulatory reasons. (Even if the total weight of the passengers sardined into it doesn't exceed the maximum carrying weight, the requirement that the aircraft can be evacuated in 90 seconds puts an upper limit on the number of passengers per exit.) The seats, it seems, aren't so much intended for budget carriers as for mixed carriers, allowing them to put in a tier below economy class, moving their lowest fares to this tier and raising the prices of their old cattle-class seats. Consequently, airlines, pressed by fuel prices and fare wars, will become slightly less unprofitable, and the flying experience will become that little bit shittier.