I’m echoing what others have said about them. Zillow is still a ‘beta’ site, and the estimates will get more accurate as more data on sales collects. Still, its kinda fun to compare the asking price on Zip with what Zillow thinks its ‘worth’..
Although I do keep a record of the week’s Zestimate, and the 2005 Tax Assessed Value in the notes section of the properties I keep on ZipRealty, on the same line as the Asking Price…it can make ‘interesting’ reading sometimes..
You can get more sensible data from looking at the comps list at the bottom of the page on Zillow, but as sales over three months old are going to be ‘aberrant’ in this rapidly changing market, it can be difficult to (Z)estimate by hand. More often than not, there will only be one or two places nearby that have sold in the last three months, so data to calculate an accurate Zestimate is often not there.
As I said in the above post, feel free to ‘take the mickey’ as they say in the UK, this is my highly unprofessional and eccentric way of looking at houses!