Blog P.I.

October 2004: 4 million blogs April 2007: 70 million blogs

The latest State of the Blogosphere report from Dave Sifry at Technorati came out last week. He also calls it “State of the Live Web,” which either sounds like he’s trying to get acquired by Microsoft or retiring the word “blogosphere” (don’t tell Bill Quick).

As always, Sifry places great emphasis on how many blogs Technorati is “tracking.” In October 2004, when Sifry first issued his report, it was 4 million. Now it’s 70 million.

In last October’s report — when Blog P.I. analyzed the distribution of blog types in the Technorati Top 100 — it was a mere 57 million.

In that report and (if memory serves) that report alone, Sifry offered a more interesting finding:

About 55% of all blogs are active, which means that they have been updated at least once in the last 3 months.

When you think of how many people have started blogs and then abandoned them, moved from one platform to another, or even kept multiple blogs open for various purposes, 55% is surprisingly high. Regardless, I did the math and concluded that the number of active blogs, using Sifry’s loose definition of “active,” was closer to 33 million.

If we assume that the number is still somewhere around 55%, then there are currently some 38.5 million blogs that meet at least some kind of semi-active status.

Sifry does offer the number of blog postings for particular periods, but he does not specifically include this number in this report — though a German blogger and a French blogger clamor for it in the comments — and he hasn’t previously offered further breakdowns: How many blogs have updated in the past month? Week? 24 hours?

These numbers would tell us a lot more about how big the blogosphere is than the supposedly awe-inspiring but mostly skepticism-inducing count 70 million “tracked.” Yes, we know what Technorati is doing, but since you’re in a position to tell us, how many active blogs are there really?

P.S. Jordan McCullum at Marketing Pilgrim tried crunching the numbers another way:

We know that popular blogs can post multiple times per day, anywhere from 5 to 20—and other active blogs may post only once every few days or once a week. If we took a stab in the dark and said that the average was once every three days (skewed to the right by the high number of “less active” blogs), that would mean that only 4.5 million of the 70 million blogs out there are “active,” or 6%. Seems a bit low, wouldn’t you say?

On any given day? That would be 11.7% of the blogs updated in the past three months. Sounds plausible to me, but only Dave Sifry knows for sure.