By comparison, right-wing blogs have pretty much only one means of finding a new voice in the blogosphere: when someone starts a new blog. The inability to operate within a community must be the primary reason behind the large number of conservative blogs in the second, third and fourth quintiles of the Blogads traffic rankings. In fact, of these 120 blogs, 77 of them are openly conservative / libertarian. There are swarms of new conservative voices looking to breakout in the right-wing blogosphere, but they are not even allowed to comment, much less post a diary and gain a following, on the high traffic conservative blogs. Instead, without any fanfare, they are forced to start their own blogs. However, because of the top-down nature of right-wing blogs, new conservative blogs remain almost entirely dependent upon the untouchable high traffic blogs for visitors. In short, the anti-community nature of right-wing blogs has resulted in a stagnant aristocracy within the conservative blogosphere that prevents the emergence of new voices and, as a result, new reasons for people to visit conservative blogs.
Unless right-wing blogs decide to open up and allow their readers to have a greater voice, I expect that the liberal and progressive blogosphere will continue its unbroken twenty-month rise in relative traffic. Conservative bloggers continue to act as though they are simply a supplement to the existing pundit class, without any need to converse with those operating outside of a small social bubble or any need to engage people within the new structure of the public sphere. In the formulation of Stirling Newberry, they view themselves existing on top of a pyramid rather than in the middle of a sphere.
This is a much more in-depth analysis than the simple hive vs. herd analogy. Worth reading.
Update, 5:17 p.m.: After thinking this over for almost five whole hours, and reading thoughts from Polipundit and Mark in Mexico, it strikes me that it's possible that reading blogs might be the intellectual equivalent of going out to protests. (Secretly, I've always thought that reading--and writing--blogs was more worthless than that even, but never mind for now.)
It could well be that the liberal temperament is more predisposed to blog-reading than the conservative temperament is in the same way that, for instance, modern American liberalism is more predisposed to protest marches than modern American conservatism is.
The size and number of protest movements, of course, means very little. In the 1990s, there were relatively few mass protest movements, but Bill Clinton was winning elections. Since 2000, there have been many big, impressive protest demonstrations by liberals--yet they've been shellacked at the polls.
(Come to think of it, maybe there is a correlation between liberal protesting and conservative electoral success?)
In any case, while it's certainly possible that the success of the liberal blogosphere is a harbinger of an important growth in liberalism, it's also possible that it's a meaningless indicator.
None of which, by the way, invalidates Chris Bowers's very thoughtful and interesting initial post on the subject.