• by Wendy Davis , Staff Writer @wendyndavis, September 24, 2007

Add world's largest focus group for marketers to the list of phrases used to describe YouTube. That's how Google's Eileen Naughton, director of media platforms, characterized the site this morning during a keynote address at MediaPost's OMMA conference.

Comparing a USA Today's post-Super Bowl survey of 238 respondents about their favorite ads to YouTube's own metrics, she posited that people's viewing habits on YouTube offered marketers better information. "Why rely on 238 people when you have YouTube?" she asked.

One answer: YouTube's demographics aren't necessarily representative of the buying public. Consider, the user-generated Doritos ad that aired during the Super Bowl placed fourth in the USA Today poll, but proved the most popular of all Super Bowl ads with the YouTube crowd.

It should be obvious that this discrepancy doesn't suggest that YouTube offers more reliable insights as much as that YouTube users -- some of whom are themselves content creators -- are biased in favor of user-generated content.

That's not to say that YouTube isn't useful to marketers. People's viewing habits on the video-sharing site certainly can offer some clues to their preferences and tastes. What's more, CBS and other content owners have found that exposure on YouTube can help their programs build an audience.

But marketers who put too much store into how YouTube viewers behave are bound to be let down if they don't also keep in mind that not everyone out there is a YouTube aficionado.