They created a software to generalize every house in existence into one category. House.
Then they used the simplest of criteria to come up with numbers that were within 23-35% INACCURATE.
Of course then they wrote a tiny little disclaimer in the smallest letters on the bottom of their MONGUL site and Twa La, some dirt bag gets rich and sinks the value of every home in America causing the hugest real estate crash in American History. Of course they have to their advantage that most Americans are in a coma and as much as they are angry NO ONE WILL CHALLENGE THEM. Its the American way..you can rape, rob and pillage people, as long as they don't take you to court, you're good.
So when will someone take Zillow to Court? When will the Zestimations end?