Interesting note from the Wall Street Journal’s Carl Bialik (by way of Frank Barnako’s Internet Daily about measuring the growth of blogs. The total number of blogs isn’t a relevant measure, Bialik suggests, since there is wide disagreement about the total number blogs (between 10 and 32 million). With new blogs being started and bloggers abandoning existing blogs, it’s a moving target at best.

Easier to track—and more pertinent—is the total number of blog posts contributed each day. According to Barnako, “That’s an indication of activity and life. Technorati says it tracks as many as 900,000 postings a day, while Blog Pulse says it sees about 450,000.”

Where Bialik fails to grasp blogs’ significance is in his insistence that low readership signifies low importance. Readership volume isn’t the point in blogs; the initial Kryptonite bike lock posts, for example, appeared on the blogs of bicycle enthusiasts that did not enjoy large audiences. What they did enjoy was a trust network among those who did read the blogs. Even if the audience for one of thee blogs was fewer than 10, it only took one to write about hit on his or her own blog and link or trackback to the original post in order to begin the rapid penetration of the message until it reached Engadget and then The New York Times.

Those 450,000-900,000 postings each day, then, can have a huge impact, even if they’re posted to blogs with limited visibility. It’s not the volume; it’s the network.