Barton, who also co-founded Expedia, said Zillow has up-to-the-day “Zestimates” (Zillow’s term for a house’s estimated value) for over 50 million properties.  According to Zillow, the average US home price has fallen 2.8% over the last year.

When asked for his predictions on the market, Barton responded, “We don’t have a crystal ball,” but added that a forecasting feature, given all of their data, could be in the near future.  “What I can tell you is that the interest in houses, and the excitement about houses, and the emotion people are feeling about houses is extremely high.  We didn’t exist a year ago, and now we get over 4 million people a month.”

Zillow is also changing the real estate agent game, adding a Web 2.0 feature called “Make Me Move” that allows sellers to “hold a for-sale flag over their house,” as Barton said.  The seller can list a price that would make them move, and according to Barton, 40,000 people have placed “Make Me Move” prices on their homes since the initiative began.  Is it enough to make real estate agents worry?  Not yet.  But it’s enough to show that Zillow signals a real relevance of the online real estate market in the new environment.