For some reason American Colleges got into the professional football business over 70 years ago. Yes, I know the fans will say the players are amateurs, but they're not. They are all being paid cash money to attend University. The star players also get cars, clothes, college jobs for their families and off campus apartments. All of this payola is against the rules. The governing body of US College football investigates over 100 Colleges each year. Both the schools and the players are well trained in hiding these transgressions.
Some colleges are better than others, insisting that the players attend class, maintain a certain grade point average and actually try to get a degree. Many of the big time college football teams (the ones even Col has heard of) don't care one way or the other as long as the star players stay out of jail and available for football. A player has four years of playing eligibility. Once the four years are up, these schools simply pat the player on the head, kick him out the door and replace him with another.
The reason for this is simple, BIG MONEY. The largest sports stadia in North America are owned by the Universities. Ticket money helps but the real money comes from TV and from the post season bowl games. The big bowls pay teams millions to play in their game. Only the best teams play in the big bowls.
Now, before I get carried away with my own rant, the money the football team earns is returned to the University. The profits from the football program supports the other sports programs at the University and also goes for academic scholarships.