Compass put out research this week saying homes shown on Zillow sold for 1.3% less than homes Zillow had banned. What they actually measuredPer Compass’ own research release, the company looked at 296,966 of its listings from January 2025 through May 2026. Compass took that gap, multiplied it against the price of a typical American home, and called it a “$5,590 Zillow tax.” Because the asking price isn’t a fact about the house. The number Compass picked is the one a smaller pool of buyers would be expected to win all by itself — whether or not the seller came out ahead.