Photo: Wendover Productions

Airline travel: Can’t live with it, can’t live without, at least if you have long distances to travel and don’t feel like taking a days- or weeks-long journey, potentially on a boat. In its new episode, the YouTube channel Wendover Productions digs into the economics of airline travel, which, yes, means an exploration of why economy-class seats are so unbearably small. The video explains that airlines don’t really make their money on economy class—they make it on the premium ones. For instance, on a British Airways Triple 7 flying from London to Washington, D.C., the 48-seat business class cabin makes the airline more than three times as much money as the entire 122-seat economy-class section. When you look at all the premium cabins combined, 45 percent of the passengers account for 84 percent of the airplane’s revenue.

Of course, there are other factors at play that the video doesn’t really go into, like the amount airlines are spending on passengers in each section (those fancy first-class meals and airport lounges can’t be cheap). But overall, it’s a solid intro to the general mind-set of an airline. The video also digs into the history of commercial flight and how airlines came up with the idea of selling the same product (i.e., flying from point A to point B) at drastically different prices. Like a game of Tetris made up of real-life people, airlines are constantly trying to figure out how to rearrange their seats to maximize their revenue.