The site lists Zestimates for each property, or Zillow's estimated market value for an individual home. The company says a Zestimate, which is "automatically computed based on millions of public and user-submitted data points," is a "starting point in determining a home's value and is not an official appraisal."
Zillow's CEO Spencer Rascoff recently purchased a 12,732-square-foot, six-bedroom, nine-bathroom house in Los Angeles for a little less than $20 million, while the site had estimated the home's price at $18.4 million, Curbed reported.
A headline on the Curbed story implied that Rascoff had "overpaid" for the house.
According to other media reports, a home that Rascoff recently put on the market in Seattle, where Zillow is headquarted, sold for $1.1 million -- about $650,000 under the Zestimate, The Real Deal reported, and a difference of about 40 percent.
A spokesperson for Zillow provided a statement in an email:
"The accuracy of Zillow's home estimates is well publicized," said Emily Heffter, PR specialist. "The published error rate for homes in that area is about 5 percent -- the difference between what Rascoff paid and the Zestimate is about 7 percent."