David Sifry and Technorati in Business Week: Tracking the Blogs:

Q: You say you welcome competition from Google, Yahoo, and MSN, should they decide to offer blog search. Why would you welcome such Net heavyweights as rivals?
A: The larger question is, is it really competition? I look at what Google and Yahoo and other companies in this space are doing, and they’re really fantastic at helping you pick out what’s the best reference site for something. You go to Google and type in wine, and it will tell you the best places to buy wine. But if you really want to find out what the world’s leading wine experts are talking about, Google isn’t really built to do that.

Q: Why can’t they build themselves up to do that with a blog search engine?
A: Well, good luck. We’ve been doing it now for almost three years, and it’s a lot harder than you think. Doing it on a small scale is not terribly difficult. Doing it to scale becomes pretty hard, and every day the blogosphere is growing by leaps and bounds.

The blogosphere today is about 30 times as big as it was three years ago. So just to give you some ideas on what that means: Every single day we’re seeing about 80,000 new people who are starting blogs. And we’re seeing about 900,000 new posts every single day. So that’s about 11 posts every single second that you’ve got to now index, you’ve got to score it, you’ve got to make sense out of all of its relevance, and you’ve got to push it to your servers really, really fast so people can stay up to date with what’s going on.

…Q: You say Google can’t tell you what wine experts are talking about, but Technorati can. How do you do that?
A: When you think about the words that we use when we talk about the Web, we talk about pages, we talk about documents, we talk about directories. What does that mean, the language, the metaphor we use when we think about the Web today?

Q: It’s a print culture metaphor.
A: Exactly. But there’s a long way to go. We’re really trying to do something a little different from that. What Technorati is trying to do is looking at the Web in a different way. And the way that I like to think of it is, it’s like this big river, it’s like this conversation flow. It’s about people and conversations.

Just as Google invented page rank, reordering the way that we sort the Web, what we did was say, “O.K., why don’t we take the same idea and apply it to people.” So the way that Technorati calculates what we call “Net attention” is we look at how many people are linking to you.

…Q: What are you working on that business users might be excited about?
A: First, there’s advertising and sponsorship. Business users can advertise on search results that have something to do with their company.

Second, we’re unveiling a new service in August that’s currently in beta testing that’s geared toward professionals — people who need a deeper view of a company or its products, such as PR people, people in marketing or advertising, financial analysts. [Basically,] people who need to track buzz, how it changes over time, who are the influencers who is talking about their company or their product. These will be subscription products.