According to Technorati statistics, the number of new web logs (blogs) is doubling every 5 months. As of October, 2005, the popular search engine was tracking almost 19 million active blogs. This phenomenal growth presents new opportunities as well as significant challenges. David Sifry, Founder & CEO of Technorati, addresses both the positive and the negative in his "State of the Blogosphere" speech at the Web 2.0 conference, held October 5-7, 2005, in San Francisco, California.

One of the positive developments is the warming relationship between bloggers and mainstream media. Sifry announces a new program that Technorati is rolling out in cooperation with several well-known news publications, in which a two-way link is created between news stories and related blog discussions. Another positive development is the rise in popularity of tagging, where bloggers add contextual keywords to their posts and enable search engines to produce more relevant results.

Of all the challenges faced in the blogosphere, the most notable is the rise of new forms of blog spam. The practice of aggregating content from legitimate sources, often without permission, and reusing it on another site in order to boost page rank and ad sales, is a growing problem. Technorati is combating the problem with new search algorithms to try to keep the problem from spreading.