Are Zillow Estimates of Home Values Accurate? Over the past few years, Zillow has become one of the most popular websites for real estate information, with 73 million unique visitors in December 2014. On this site, visitors can search through active listings from around the country, find general information about homes on and off the market, and also look up a home’s current value as determined by Zillow, called a Zestimate®. Given its dominant presence in the real estate market, many home buyers and sellers often don’t want to budge from Zillow’s estimated value when either buying or selling a home.