Web logs have had an astonishing season this year, enough to freckle the faces of bloggers who do not, as a rule, get much time outdoors.

Although political blogs have received the most attention, advertising agencies and communications professionals are using blogs to create discussion about ideas within their industries.

Butler, Shine, Stern & Partners in Sausalito, Calif., produces a blog, Influx Insights (www.influx.bsands .com), that includes discussion of video game marketing. Yellowfin Direct Marketing in Boston has commented on the politics of emotion and the art of client service on its blog, A Fine Kettle of Fish (www .afinekettleoffish.blogspot.com).

Urban Advertising in New York has a blog on industry trends, Urban Intelligence (urbanadvertising.com /intelligence).

And Richard Edelman, president and chief executive at Edelman, part of Daniel J. Edelman, began writing his own blog (www.edelman.com /speak_up/blog) on Sept. 29, most recently recounting his travels through India.

Agencies with blogs , though, are in a minority. For many, particularly the large networks, the potential risks still outweigh the benefits.

"Blogs are in fashion, and it is easy to hop on the bandwagon and say that every company should have one," said Linda Sawyer, managing partner and chief operating officer at Deutsch in New York, a unit of the Interpublic Group of Companies and an agency without a blog. "The questions any smart marketer should be asking are, 'Does this provide a platform to connect with their most relevant audiences and how will this address business objectives?' "

"That's not to say we would never enter blogland," Ms. Sawyer said, "but there is a fine line between being timely, topical and keeping current while making sure that we are doing what's best for our business long term."

The biggest fear is an uncontrolled message slipping out, said Steve Rubel, vice president for client services at CooperKatz & Company in New York, a public relations agency with clients including the Association of National Advertisers, J. P. Morgan Chase and Wendy's. "Do they allow comments or do they not? Is there an implication if it is a publicly traded firm? Who is the one who should blog for us? How might that choice be received in the company?"

"Ultimately this will all work out," said Mr. Rubel, who writes a blog called Micro Persuasion (www .SteveRubel.typepad.com), focusing on the effects of blogs and other embodiments of "participatory journalism" on public relations. He also consults with the Association of National Advertisers on matters including its two blogs (www.ana.net/blog).

One is called A.N.A. Marketing Musings and is written by Robert D. Liodice, president and chief executive at the association. Dan Jaffe, executive vice president for government relations and head of the Washington office, writes the other, called A.N.A. Regulatory Rumblings.

Mr. Jaffe said blogs were popping up everywhere because people want an improved ability to learn and communicate in real time. "One of the things I do is represent the advertiser industry," Mr. Jaffe said. "Most of the time you can intuit what people's views will be. But in those areas where that's not the case, then getting feedback is critical."

Regulatory Rumblings is neither the only tool nor a perfect one, Mr. Jaffe said, but it maintains dialogue better than the tools of two or three years ago.

The growing number of professional blogs often lack the qualities that made earlier blogs big hits: attitude, irreverence and an apparent interest in kicking up a fuss. Gawker, the Manhattan gossip and media blog published by Denton Media, demonstrated the form last night when it posted, "Kate Winslet Shops for Food but Might Not Eat It."

Agency blogs serve different functions, said Bernard Urban, president at Urban Advertising. "It's allowing people who visit our agency site to get a feel for who we are without even having a conversation with us," he said. "We have a living point of view."

Steve Hall, editor and publisher of Adrants (www.adrants.com), a blog commenting on advertising and media matters, said that blogs open windows for people. "Most corporate agency Web sites are really just fancy billboards," he said. "It's pretty much impossible to have a face-to-face with every single business contact out there. What better way than to put your voice out there on a regular basis with a Web log?"

A limited number of blogs, like Daily Kos (www.dailykos.com), have started collecting advertising revenue from marketers interested in reaching sharply defined and tech-savvy audiences. Now advertising itself could emerge as a potential function of agency blogs, too.

Bob Cargill, senior creative director at Yellowfin and the originator of its seven-month-old Kettle of Fish blog, said the broad purposes were sufficient for now. "The idea is to attract people to our Web site, not to promote our own agency or even our own clients, but to promote issues, tactics and techniques."

Down the road, Mr. Cargill said he has bigger ambitions. "My goal is to make this not just a Yellowfin blog, but an industry blog all about direct marketing and advertising, with thousands of subscribers and possibly ads."