At $100,000 per second, Super Bowl ads are already expensive. But the success of spots like Doritos and Pepsi Max this year proves that the big guys don't have to pay ad firms to make the ads.
Simply hold a contest and crowdsource it.
Fans devise the creative and fans vote on their favorite. You don't have to pay to make it or to hold focus groups. And what the success of these ads prove is that just because they've been posted online well in advance of the game — for the voting — doesn't diminish the impact of the ad.