This time last year, the advertising world was abuzz over the user-generated Doritos Super Bowl spot. This year, no one’s doing UGC commercials. The Super Bowl is safely back in the arms of Madison Ave., leaving the average Joes behind.

“At that time, UGC was something that was a little on the rise,” said Rudy Wilson, director of marketing for Doritos. “There was this idea of people creating their own commercials. How do we make it the Doritos way?” And naturally the Super Bowl offered the best opportunity for getting the ad seen.

But like so many novel ideas, a ton of followers jumped onto the UGC ad bandwagon, yielding diminishing returns. Win the Doritos contest, your spot aired during the Super Bowl; win the Dove contest, your spot aired during the Academy Awards; win the Heinz contest, your spot aired during the Primetime Emmys; win the Kraft contest, and you’ll see your ad “made into a national commercial in 2008.”

A UGC ad isn’t so super when everyone’s doing it.

“We might have hit the peak last year,” said Wilson, who noted that a lot of users created their ads for the exposure. “Once you hit the biggest stage, the question becomes, what next?”

Sizable cash prizes were still offered for all of these contests — the winner of the Kraft ad took home $50,000 while the Doritos winner pocketed just $10,000 — but the problem is that when you raise the dollar amount, you appeal more to the contest-entering set, as opposed to the skilled professionals looking for exposure. So the quality of UGC ads submitted won’t be as high.

“For Doritos fans, we’re talking about teens and young adults,” said Wilson. “Their interests change on an ongoing basis. What we learned is that you have to get on these interests at the right time and you have to be authentic.”

Big brands stay big brands by protecting their, well, big brands. I spoke with Neil Perry, CEO of UGC ad firm XLNT Ads last year, who said at the time that his company was refocusing onto smaller to mid-size brands that were willing take more risk.

And the UGC world can be risky. Chevy learned first-hand what happens when you make your UGC contest too open — users uploaded spoof commercials that made fun of the gas-guzzling Chevy Tahoe. And as The New York Times recently reported, Subway, Quizno’s and iFilm are heading to court over a UGC commercial contest in which Quizno’s openly called on participants to create video spots that bash rival sandwich shop Subway. The contest was held in the fall of 2006; the trial isn’t scheduled to start until 2009.

But despite all this, there are some signs of life for user-created commercials. XLNT Ads just signed Nestle to use its UGC approach. And a company out of Vancouver, Canada, called Memelabs is hoping to build a business out of UGC ads for companies, and has already landed clients including Wells Fargo (you could catch that winner during the Rose Bowl Parade).

Even Doritos entertains the possibility of revisiting UGC commercials. “If they [Doritos fans] want to do that again,” said Wilson, “I’m open to it.”