A new study from comScore Networks today found that nearly 50 million Americans, or about 30 percent of the total U.S. Internet population, visited top blogs in Q1 2005, representing an increase of 45 percent compared to Q1 2004.

The study, funded by Six Apart and Gawker Media, looked at the internet habits of 1.5 million Americans and when they visited the top 400 blogs online, but excluded the rest of the blogosphere.

Other key finding include:
- Of the top 400 blogs, segmented by eight categories, political blogs were the most popular, followed by “hipster” lifestyle blogs, tech blogs and blogs authored by women
- Compared to the average Internet user, blog readers are significantly more likely to live in wealthier households, be younger and connect to the Web on high-speed connections
- Blog readers also visit nearly twice as many web pages as the Internet average, and they are much more likely to shop online

“The fact that we found 30 percent of the online population to have visited blogs clearly underscores the commercial importance of consumer generated and driven media,” said Dan Hess, senior vice president of comScore Networks. “It’s noteworthy that while the blog audience is already quite large and growing, its demographic composition relative to the total
population will appeal to many marketers.”

The full study is available here (pdf)