Yahoo!'s running an article about a study from the Pew Internet and American Life Project. The result of their study? Blogging Still Infrequent It's an interesting article that seems to downplay the prevalence of blogging in general, but it also points out, "That survey [in May '03] found only 2 percent of users keeping blogs, although a preliminary analysis of follow-up surveys from early 2004 showed the figure increasing to about 7 percent."
Two percent to seven percent? If I was writing this article, I might feature that 250% growth more prominently. I think the message from the study is clearly that blogging is gaining a lot of momentum.
Take a look at A's Blogs alone. I launched my site in November, but didn't post anything about the A's until 12/2/2003. AthleticsNation's first post came on 11/7/2003. Baysball, now part of the all-baseball family, originally launched (as far as I can tell) in 3/03. Barry Zito Forever (BZF) launched with their first post in August of 2003. Elephants in Oakland is a dinosaur by comparison, with his first post coming way back on 8/1/2002.
So, you've got one site launching way back in late 2002, one in early 2003 and three in late 2003. To me, that's the beginning of a trend. But the Pew study is right, however, that the (growing) number of A's blogs is still quite small when compared to the total number of A's fans on the internet.