This upcoming Sunday is the biggest sports day of the year in the United States: The championship game for the professional American Football league. The entire country grinds to a halt.
The most famous secondary effect of the game is the commercials. So many people watch the game that television advertisement costs are the highest for the Super Bowl, which means that companies will produce spectacular ads specifically for the Super Bowl, which means that more people watch the Super Bowl just for the ads.
Another secondary effect of the Super Bowl is the spike in chicken wing sales. The United States chicken industry even issues an Annual Chicken Wing Report. NPR explains how the chicken wing became the dominant snack food for the Super Bowl.
Bonus viewing: A Guide to American Football.