While the He Gets Us campaign is best-known for its Super Bowl ads — last year’s spot, featuring people washing each other’s feet, went viral — the sprawling PR effort is everywhere: the MLB World Series, the NBA and NHL playoffs, and on top of a NASCAR racecar; there was an ad during the Grammys this week.

There is no better opportunity for advertisers than the Super Bowl, which is watched by an average of more than 100 million Americans each year. Naturally, the price of running a commercial during the game is enormous.

Is millions of dollars for 30 seconds of air time really worth it? Here's a timeline of how the Super Bowl became the most expensive night in advertising.