First, let's step back and consider why we're counting blogs at all. You no longer see articles that attempt to demonstrate the legitimacy of the Web by stating how many Web pages there are. But blogs are still in the process of entering mainstream consciousness, so numerical credibility is important; bloggers themselves cite the statistics a lot.
It turns out that counting blogs isn't as hard as counting Web pages. When writers who use common blogging software want their blogs to be publicized, they choose to automatically "ping" computer servers for companies like Technorati Inc. (www.technorati.com
) and Intelliseek's BlogPulse (www.blogpulse.com
), whose goal is to measure and index blogs. Then Web users can go to those companies' Web sites and run searches to find blogs that have written about topics they're interested in. BlogPulse now indexes about 11 million blogs world-wide; Technorati, about 10 million. Over the past six months, both have seen a doubling in the number of blogs on the Internet.
Pinning Down Readership
The number of blogs doesn't tell us much about the medium's relevance. How many people are reading blogs?
In a telephone survey of U.S. Internet users last fall, the Pew Internet & American Life Project found that 27% of respondents said they read blogs. (Users were asked: "Please tell me if you ever do any of the following when you go online. ... Do you ever read someone else's web log or blog?") But in the same survey, Pew asked: "In general, would you say you have a good idea of what the term Internet 'blog' means, or are you not really sure what the term means?" Just 38% of Internet users answered "yes." Of the 27% who said they read blogs, about 40% answered "no" to the blog-awareness question.
In an update to the survey earlier this year, Pew reported that 25% of Internet users said they read blogs -- a small decrease from the 2004 results. The blog-awareness question wasn't asked that time around. Multiplying the results with Pew's estimate for the total number of Americans online yields an estimate of about 32 million American adults who read blogs. That number is frequently cited in press coverage of blogs.
How Important Are They?
Even if millions of Americans read blogs, there are very few individual blogs that have a significant number of readers. Several Web sites attempt to rank blogs for popularity, but it's not always clear how they arrive at their numbers.
Little Green Footballs (littlegreenfootballs.com) -- Charles Johnson's conservative blog that rose to the top echelon of blogs with its coverage of CBS's flawed report on President Bush's National Guard service -- is ranked No. 4 in rankings published on The Truth Laid Bear, a site often monitored by bloggers. But Little Green Footballs is 12th on Technorati's top 100 list. Both rankings evaluate blogs based on how often they are linked to by other Web sites, though Truth Laid Bear limits its universe to an "ecosystem" of about 23,000 blogs, thereby diminishing the number of blogs in contention and the number of incoming links.
ComScore Media Metrix and Neilsen//NetRatings are the sources most often used by online advertisers to track unique visitors. Neither tracks blogs as a matter of course, though comScore did look up traffic for 13 prominent blogs in April, upon my request (I picked ones from the top of the various rankings). Just five met the company's minimum threshold for statistical significance of about 150,000 monthly visitors. Media and gossip site Gawker had the most, with 304,000 unique visitors. The others that cleared the cut: Defamer (287,000), Boing Boing (250,000), Daily Kos (212,000) and Gizmodo (209,000). Among those that didn't were prominent political blogs Instapundit, Power Line and Eschaton. (I asked NetRatings about the same 13 blogs, and it had reportable data only for Defamer, Daily Kos, Boing Boing and Gizmodo -- and the sample sizes didn't meet standards for statistical significance.)
ComScore and NetRatings both recruit panels of online users who agree to install software that monitors their behavior. The companies use sampling techniques similar to those of political pollsters.
By point of comparison, comScore says the New York Times's Web site had 29.8 million unique visitors in April.