Airlines can make a lot of money by flying to the right places. British Airways, for example, long-ago cemented themselves as the leader on the London Heathrow to New York JKF route, and flying between these two airports now earns them over $1 billion per year. That's more than any airline makes on any other route in the world. Conversely, though, airlines can lose a lot of money by flying to the wrong places. American Airlines, for example, recently cancelled their Chicago to Beijing flight as it was loosing them tens of millions of dollars per year. Now, the fact that this route failed might be puzzling considering it flew between the world's fiftieth and the world seventh largest city. Even more, they were flying the 787-8 Dreamliner, the smallest plane they could on this route. Nonetheless, it was truly a financial disaster. The airline said that, in terms of annual revenue, the route was $ 80 million away from their target. The truth is that deciding where to fly is a lot more complicated than pairing up the largest cities. It's an art that people spend their whole lives mastering and the difference between an airline that's good at route planning and one that's bad. This can be the difference between a profitable airline and a defunct one.