[tbrownaw]

Another way of looking at this would be to point out that internet service and air travel are the only two industries where it is legally allowed to sell people something you know in advance you can't provide.

There's also fractional-reserve banking, hotels, old-style phones, online / mail-order shopping ("sorry, your stuff is in back order"), etc.

Statistical arbitrage is a thing.

[Karunamon]

Hotels tell you when they're full and stop accepting bookings, nobody is selling anything at FR banking, everywhere I shop online tells me when their stuff is known out of stock, and so on.

Air travel does none of these things. They know they've sold more than they can provide, and do nothing to tell people until the last possible minute just to make a buck.