I heard about it on NPR. It is really neat. The reason 90 million of the 100 million houses are on it is because it uses GPS technology to know where you are and then just like Shazam can tell you the name of the song you are listening to is, it tells you what house you just took a picture of (the yellow one on the north east corner, etc). The values come from either MLS data if the house is for sale or tax data if it is not. The problems tend to come from situations where all the houses in a neighborhood look just alike or the houses are too new for the values to hit any databases that it has access to. I think it is a good tool for grins and kicks (take a picture of your bosses house to know if he is a real baller or not). I would treat it like Truila or Zillow, I would not build a business model from it.