A sport is not a business. You can make a business out of a sport, in the same way you can make a business out of sex or alpaca hair or tomatoes,1 but you'll be selling something that's tangential to the sport itself. The NFL doesn't sell "football"; it sells access to the best football players. Fans buy that access in the form of game tickets. NBC buys it in the form of broadcast rights, then airs the game to attract a TV audience whose sports-captivated attention it can sell to a sports-advertising firm hired by Gatorade, which is selling a drink people might choose to consume while playing a sport.
Sport generates economic activity, but sport isn't inherently economic. Sport is just some people playing a game. You could argue that playing a game is always an economic activity on some grad-studenty, breathing-is-an-economic-activity level, and you'd probably be right, I don't know. I have a PhD in economics, but I made it myself, out of graham crackers. The point is that if you got rid of the whole system of professional American sports, just handed it over to the North Koreans and let Kim Jong-un plumply deliver his Glorious Leopard Make Wrong Sunday Ticket Decree,2 football would still exist, would still be played, would still saturate the culture in all kinds of ways, even though there would be no NFL and Football Night in America would draw a Nielsen rating that could only be represented by a drawing of a bomb landing on a sheep.3
A sport is not a business. I'm working my way through this point because I'm about to talk about two of my least favorite things — Sepp Blatter and the question of whether soccer will ever make it in America — and I want to get a little armature in place.