If there’s a better way to introduce me to a new software as a service offering than by informing me that my loft is worth a hundred grand more than what I paid for it last spring, I don’t know what it would be. But that’s exactly what Zillow did yesterday evening when I checked it out via Digg. Unsurpringsly, Zillow is my favorite new Software-as-a-Service application. Ever.
But even setting aside the fact that the amount is likely off by a fair amount  – Nicholas Carr says Zillow was out of date for his place, and in truth Zillow’s sq footage for my establishment was off by a hundred feet or so – this is a remarkable new service.
Not so much because of the interface, which is slick and capable, if not truly groundbreaking in a Google Maps fashion. What’s truly compelling about the application from the founders of Expedia, rather, is the degree to which is renders transparent something historically very private. Want to know what your friends house is worth? Look it up. Interested in seeing how much your friends’ parents paid for their new McMansion? Odds are, it’s in there. By opening up data that was previously ministered only by the high priesthood of realtors, Zillow has in one fell swoop changed the landscape of what’s public and what’s private.
Besides the privacy angle, which is likely to concern many, the other salient point worth calling out is the impact it has on existing businesses, i.e. realtors. In the PI piece linked to below, Zillow’s competitors are already going out of their way to FUD the service, calling it a “Wal-Mart entering the territory of a small retailer.” And undoubtedly there is some truth to that; portions of what Zillow provides would have been difficult, if not impossible, to extract without the services of a professional realtor. In that respect, Zillow is all about paying attention to the man behind the curtain.
Zillow may be, however, but one example of what can occur once previously disparate or closely held data stores are integrated with other relevant data. The resultant recombined data feeds might be lethal to those who prey on customer ignorance, but a real boon for businesses that can leverage and differentiate off the data.
In any event, I suggest you give Zillow a look if you haven’t already.
 The Seattle PI does mention, however, that the Denver market is particularly data rich and therefore off by less than 5 percent on average.