My "Zestimate" dropped down to almost half in one month.How does Zillow determine the "zestimate" of one's home? My house's zestimate was around 1.3 million a month ago and is now $698,000. What am I missing? Maybe a toxic waste dump has been discovered near by? Help!November 25 2013 - Roscoe Village00YesReport a ProblemProblemSelect oneOffensive contentIrrelevant contentSpam (pure self-promotion)OtherDetailsYour emailPlease enter a valid email address.Submit CancelContent flaggedWe will review this content. Thanks for helping make the site more useful to everyone. To learn more, read Zillow's Good Neighbor Policy.We're sorry. This service is temporarily unavailable. Please come back later and try again.