I agree that you really have to take a grain of salt with Zillow estimates. I don’t know too many people that take them too seriously anyway. I agree with kev374 that they have some good information on it and some good graphs for property tax history, etc.
But it sounds like many of the people that are angry are people that had their valuations suddenly go down. I’m buying a house and the valuation went up $25,000 in 1 day after the change.
But that doesn’t mean anything because the price I negotiated is almost 15% lower than the median comps right now. Zillow estimates mean nothing.
