A 30 second ad-slot in this weekend’s Super Bowl can cost as much as $4 million. What explains the fact that since 1980 Super Bowl viewership has only increased by 50% but advertising prices have seen a shocking tenfold increase? Slate reports:

• The NFL is the only type of television event that is able to draw a wide audience.
• Research suggests that companies that buy Super Bowl ads see their share prices outperform the S&P 500 in the subsequent week. This relationship holds despite controlling for several factors.
• It is unclear if this is a short-term irrational burst in investor exuberance, or if the ads actually create lasting value.
• Other studies suggest that movies that are advertised during the Super Bowl can see up to a 40% boost at the box office.

To read more about the history of ad prices in the Super Bowl as well as reasons why people might over-pay for Super Bowl ads click here.

Source: Slate