By the end of 2008, Technorati (www.technorati.com), a blog search engine, tracked 133 million blogs worldwide, totaling 900,000 million posts daily. (..) not all blog users visit political blogs (27% during 2008, according to Pew Research Centre for the People and the Press, 2008), and that only 3 percent of blog posts at any given time can be classified as political.
De Zuniga, Homero Gil, Puig-I-Abril, Eulalia, Rojas, Hernando (2009) Weblogs, traditional sources online and political participation: an assessment of how the internet is changing the political environment. New Media & Society, 11(4).