Sifry: Tracking posting volume

Technorati’s Dave Sifry is pushing out their company’s the blogosphere data. You can find new data, charts and more on his blog.
One (new) metric he’s discussing, that I want to talk about, is posting volume–in other words what are the aggregate number of posts per day (this is a good number to measure consistency and commitment among blog owners.)
Sifry says posting volume has doubled in the past 9 months and that Technorati is tracking about 500,000 posts per day, compared to about 400,000 posts per day in Oct 2004.
Although Sifry agrees that these figures could be squewed by squewed by the US election, the tsunami and similar events, that’s still an interesting number–and one it will be go to track going forward.