Zillow is completely useless, unless you are a realtor. I own a couple properties in a high rise, and listed one for rent. I am not a realtor, but I thought the site might be helpful. On the day that I listed one unit for Rent (October 1,2013), the "zestimate" was $272,000, and the rental zestimate was at $1900. Today is November 18,2013, and my condo "zestimate" is now 206,000 and the rental zestimate is 1671. The housing market has improved in my area over the past 2 months, and comps for the unit in question have sold for mid 260's this month (exact same floor plan, 3 floor above and 3 floors below). I did send an email complaining to zillow about why my property value has dropped significantly. I received a canned response stating that zillow evaluated based on comps. Of course, since I'm not a realtor, this site has artificially tanked my property value. Now, I disclaimed ownership of the condo, and noted that it just sold for $5,000,000. Let's see how zillow reacts to that.