Do blogs matter?

I have heard that once a "hot new technology" makes it onto the cover of Business Week, it's already on the road to mainstream.  Blogs have been heading that way since all the publicity during the 2004 election around the "citizen journalists", and even before.  But do they matter outside politics?  Apart from providing information, can they really have an impact on an organization's bottom line?  Apart from often quoted stats from Pew Internet about the number of people reading blogs, I believe there are other significant signs that companies should take their impact very seriously:

1. Journalists are reading them, and using them as sources for stories and background research
2. Many popular "A-list" bloggers are extremely influential among their readership (often more so than any other third party source)
3. Blogs are often returned in the top five search results on Google and other search engines because they are so search engine friendly (and more than 80% of users don't venture past the first page of search results)
4. Blogs can be one of the most viral forms of good or bad publicity, with cross linking, comments, and trackbacks - enabling a message to travel many times beyond it's original audience
5. With the eroding public confidence in mainstream media, and growing cynicism and ability to filter out advertising (Tivo, Firefox Ad Blockers, etc.) - blogs power to influence is growing because they remain one of the few genuine voices of truth in the media landscape (if done right)

As a recent example of how blogs matter, check out this post from AdPulp about prominent blogger Jeff Jarvis (BuzzMachine) and his recent problems with a new Dell computer.  Jeff's bio is "former TV critic for TV Guide and People, creator of Entertainment Weekly, Sunday editor and associate publisher of the NY Daily News, and a columnist on the San Francisco Examiner" - in short, a pretty credible and influential guy.  When he has problems and writes about it, it makes for a pretty compelling reason to avoid Dell computers and choose a different brand.  When I read his article today - there were 9 comments.  I bet there will be lots more by the end of the week.