] By the end of 2004 blogs had established themselves as a
] key part of online culture. Two surveys by the Pew
] Internet & American Life Project in November established
] new contours for the blogosphere: 8 million American
] adults say they have created blogs; blog readership
] jumped 58% in 2004 and now stands at 27% of internet
] users; 5% of internet users say they use RSS aggregators
] or XML readers to get the news and other information
] delivered from blogs and content-rich Web sites as it is
] posted online; and 12% of internet users have posted
] comments or other material on blogs. Still, 62% of
] internet users do not know what a blog is.

Full report here...

Pew Internet & American Life Project: Blogosphere