Lawler's Rule

Who decides which cities to display on airline flight maps? You know the maps that show your departure city, the little image of a plane, the arrival city, and then all sorts of useless information like the distance remaining in meters. There are always 3-5 other cities shown on the map and I can't understand how they determine which ones make the cut. Usually, the group will be something like: New York, Chicago, Detroit, and Toledo. Why did Toledo make the cut? Shouldn't they at least put one of the other (larger) Ohio cities up there? I don't get it.