Let's talk about mistakes. They're part of life; everyone makes them—even airlines.
In 2014, I happened to be reading my Twitter feed one afternoon when one of the accounts I follow tweeted that a major US airline had fares to Europe that were significantly below what would be expected. At the time, the cheapest fare from New York to Vienna was around $800, but the advertised fares for a select number of dates were between $350 and $450. This seemed too good to be true. But it wasn't. I had lucked upon what's known in the industry as a mistake fare.
In the super-secretive society of travel hackers and mileage junkies, it's well-known that airlines occasionally—and accidentally—post fares that exclude fuel surcharges. And remarkably, this isn't the only type of mistake they make. You might expect...