I see no problem with overbooking, as long as they're transparent about it and compensate people. Overbooking is common in many industries. The article holds up hotels and car rental agencies as examples of how it's done better, but those overbook too. Car rental agencies in particular don't really know how many cars they'll have available at any given time because their contracts are so flexible, so your "reservation" is really just a planning tool so they can try to shuffle inventory around. (The TV documentary series "Seinfeld" did an episode on this.)
