Yes, that's exactly it. The "Zestimate" is often way off, and the owner knows a lot more about it than Zillow does. If the Zestimate price is lower than the buyer thinks they can get, they won't take the offer. If the Zestimate price ignores the run-down condition of the house or other issues Zillow missed, they snap that up. So Zillow mostly wound up with the homes that they overvalued.