"I'm actually skeptical about the ability of advertising to affect word of mouth," Denton said at a discussion about advertising on blogs. He added that ads on the 14 blogs he publishes haven't yet produced much buzz among blog readers. "I can't really point to any examples of posts that originated from ads themselves."

Rather, Denton advised, marketers should purchase ads on blogs for the same reasons they purchase ads on other media--to reach consumers in target demographic groups.

Some other panelists were more optimistic about the prospect of blogs creating word of mouth. Steve Rubel, vice president, client services of the public relations firm CooperKatz & Company, said that advertising on blogs assisted marketers in "finding the customer evangelists out there" and "empowering them with tools."

Shawn Gold of Weblogs--a collection of blogs, including the high-tech Web log Engadget, that were recently acquired by America Online--added that word of mouth about products largely comes from organic posts about new products.

"Blogs are serving as public platforms for early adopters," Gold said. When they write about products, the posts can function to connect the products to consumers beyond just those who tend to be the first to purchase something new.

Gold also said that the ads that have worked best on Weblogs' collection of enthusiast blogs are advertorials. "The text-based ads are performing better than the dynamic ads," he said.

Denton added that not all marketers were a good match for blogs. Earlier this year, CheapTickets.com pulled its ads from Gawkers' travel blog Gridskipper after it ran a racy post about sex tourism in Thailand. Currently, he said, big brands wouldn't be a good fit with Gawker Media. "Wal-Mart would not be an appropriate advertiser for our site," he said.

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