to Unveil Blog and Feed Search today is set to unveil a new blog and RSS feed search, which will be available both on and IAC’s Bloglines Web-based feed reader.

The blog search feature is the latest tool on the new, which underwent a redesign and rebranding in February. The new search results could impact traffic to blog publishers of all stripes, including ad-supported players and authors of corporate blogs.

“People know there’s information out there, they just can’t get it fast enough,” Ryan Massie, senior product manager at, told ClickZ. “Our search gives users access to tools to find everything they’re looking for.”

The blog search results will not feature ads at launch. “We’re focusing on driving usage right now,” Massie said.

This is the first time since IAC acquired Bloglines a year ago that it will feature’s ExpertRank algorithm in its search. ExpertRank, formerly known as Teoma, improves relevance by giving more weight to links to a page from other sites within the site’s category, which presumably would be more relevant links from subject-matter experts.

“We look at the Web by breaking it down into subject-specific categories,” Kaushal Kurapati, director of search product management, told ClickZ. “A site that ‘pops’ within its own category would be considered more useful.” will also weigh subscription data from Bloglines, including historical data going back for five years. That should also increase the relevance of the results, Massie said. “When a blog or feed has a number of subscribers, it lends a certain authority and quality level to the content,” he said.

The blog search tool will pick up a feed that has even one subscriber in Bloglines, though that would certainly affect the ranking, Kurapati said. To get the best results for a blog post, a publisher should first make sure the content is useful and worth linking to by others, which will improve its ranking, he said.

Kurapati admits that, like any system, parts of the ranking algorithms can be gamed, such as by artificially inflating the number of subscribers by manually signing up for a feed from multiple Bloglines accounts. That should be outweighed by the other parts of the algorithm, he said, as well as the “power of community” that will cause relevant posts to rise to the top.

The same search technology will be deployed on Bloglines itself, but with advanced features exposed to cater to Bloglines’ “prosumer” audience. Bloglines search will make it easy for users to filter results based on ExpertRank, Bloglines subscriptions, time, and other variables.

It will also include links to subscribe to the blog or feed right from the results page, using Bloglines, Google, NewsGator, Yahoo, or another RSS reader. Users can also post the results to their own blog, or to social media sites like Digg, or NewsVine.

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