The NFL keeps firm control over its trademark on the words “Super Bowl,” and that control makes the league a whole lot of money.
The Super Bowl (we can say it, because here at SB Nation we write about sports) is a $13 billion-per-year industry, and the league trademarked the phrase in 1969. The NFL stands to lose a lot of cash if it doesn’t control the trademark. It’s worth noting, though, that the NFL may go a little overboard with it.
In 2007, the NFL sent a cease and desist letter to a church in Indiana for selling tickets to a Super Bowl party in support of the hometown team, the Indianapolis Colts. The Colts were facing off against the Chicago Bears, and the league obviously didn’t have a problem with the church supporting the Colts. They did, however, want that church to steer clear of calling it a “Super Bowl” party.
Private citizens are fine to use the phrase without consequence, as long as there’s no financial consideration involved. For others, there are ways around it. You’ll hear advertisers call the Super Bowl “the Big Game,” or some people might go the Stephen Colbert route and call it the “Superb Owl.” Steering clear of Super Bowl is a wise move, though, unless they want the NFL to come after them.