Miller-Samuel's Jonathan Miller has some comments on AVM's and Zillow.
"A few months ago, a national lender told me that out of the 10 major automated valuation services (AVM’s), 8 were totally unreliable, 1 was marginal and 1 was pretty good. This lays the groundwork for my initial skepticism about Zillow, but I am open minded. I think it will evolve and will have more strength in certain markets than others depending on the data they are fed."
Read the entire story at Curbed.com