Compare this with the airline industry. What protects Delta from competition enough to allow profits? Not very much. In fact, airlines have historically struggl

Compare this with the airline industry. What protects Delta from competition enough to allow profits? Not very much. In fact, airlines have historically struggled to show profit since deregulation. In the last few years they've finally had some profits, but a tiny amount in comparison to the decades of taking on debt. Still, the airlines keep going.