Pepsi cut out the market research middleman and let users make and vote on ads. Result? Most memorable Super Bowl ad of 2011.

Apparently, a video of a pug knocking down a glass door on top of some guy is a good way to sell junk food. But Pepsi didn't spend millions doing market research to come up with the concept, called "Pug Attack." Instead, the company leveraged its most valuable marketing device: you.

The pug ad was part of the "Crash the Super Bowl" contest, which Doritos has been doing for five years. This year, the contest was fueled by a new collaboration between Pepsi's (PEP) Pepsi Max soft drink and corporate cousin Frito-Lay chip brand Doritos. The contest is one of several efforts by Pepsi not just to engage its consumers in social media, but to start deeply-involved, closely-watched dialogues with Pepsi-drinkers. More