Compass data suggests listing on Zillow comes at a cost
The brokerage released an analysis of its listings showing that those posted on Zillow sold for 1.3% less than “banned” listings. Some experts disagree.
Key points:
- A Compass study published this week compared roughly 296,000 of its listings posted on Zillow over a 15-month period to 806 that were banned from the portal.
- The report concluded that listings on Zillow sold for 1.3% less, on average, with a lower sale-to-list price ratio — a disadvantage Compass referred to as the “Zillow tax.”
- Because the datasets were vastly different sizes and study details were limited, some have questioned the results, with one real estate educator saying it was “obviously a marketing piece.”
Listings that appear on Zillow sell for less, Compass International Holdings claims in a new report, making the argument for the second time in less than a week that phased marketing is the best way to sell a home.
'Zillow tax' costs sellers thousands
In a new analysis led by Compass Chief Economist Mike Simonsen and Chief Data Officer Dave Crosby, Compass says homes listed on Zillow sell for 1.3% less, on average, than those "banned" by the portal for violating Zillow's Listing Access Standards. For homes priced at the median existing-home sale price of $430,000, that "Zillow tax" is costing home sellers $5,590, the report said.
According to the analysis, the median sale-to-list price ratio for the banned listings was 100%, versus 98.7% for the listings published to Zillow. Meanwhile, 50.5% of banned listings sold at or above their list price compared to 44.6% of listings not banned from the portal.
The study reviewed nearly 300,000 Compass listings, the vast majority of which were posted on Zillow, between January 2025 and May 2026. Only 806 listings were banned from Zillow's platform, meaning they were marketed by Compass but not posted on the leading search portal. The report did not say if those listings were displayed on other sites, such as Redfin, which partners with Compass, or Homes.com, which has previously offered to display any listings banned by Zillow.
Time on market, the report noted, was not significantly different for the two sets of listings.
Pinning the blame on Zillow's 'lead-gen' priorities
The "Zillow tax," Compass argued, is a reflection of the portal's business model. Zillow was not created to help homeowners "protect" their property's value, the report suggested, but instead serves as a lead-generation site "built to make Zillow money at the expense of sellers."
In an Instagram post published Wednesday in tandem with the study, Compass International Holdings Chairman and CEO Robert Reffkin said the information Zillow publishes about a home contributes to its devaluation.
"When Zillow.com displays negative insights on your home like days on market, price cut history, algorithmic Zestimates less than the home's value, climate risk, flood risk, and fire risk (all unofficial risk scores), money gets left on the table," Reffkin wrote.
Does the analysis hold up?
Compass limited its study to listings affiliated with the brokerage's agents, and it compared sets of vastly different sizes: 296,160 listings published to Zillow and 806 listings not published to Zillow.
Zillow Chief Economist Mischa Fisher called the study "unserious" and something "that any high school student would earn an F for turning in."
"It is another increasingly desperate attempt by Compass to hide seller harm as a way to justify their commission-hoarding business model," Fisher added in a statement emailed to Real Estate News.
Sara Coers, who has a background as a real estate appraiser and is director of the Indiana University Indianapolis Center for Real Estate Studies, told Real Estate News the analysis was "obviously a marketing piece."
Coers pointed to the disparity in the sample sizes, the lack of evidence that Compass controlled for other variables, and the fact that only Compass listings were analyzed as flaws in methodology.
An independent economics firm not associated with the real estate industry contacted by Real Estate News said it was unable to comment on the study's findings due to a lack of complete information regarding methodology, including assumptions and limitations.
Real Estate News reached out to Compass requesting more information about the study, but a spokesperson for the brokerage said they had no additional details at this time.
An ongoing fight with Zillow
The latest study follows a separate report Compass published last week that argued its phased marketing strategy — an approach that conflicts with Zillow's listing standards — provides sellers with an average 4.6% premium on their home sale price.
"If Compass believes being on Zillow doesn't work, it is curious that Compass has made such a sustained effort to force its listings onto Zillow," Fisher said.
Compass sued Zillow in 2025 over the portal's listing standards, which caused some of the brokerage's listings to be excluded. The lawsuit, which was later dropped, referred to Zillow as "the vital, go-to destination for consumers looking to purchase homes." In a hearing related to the suit, Reffkin testified that Compass was being harmed by the listing policy and "would have grown much more if there was no Zillow ban."
More recently, Compass, alongside Midwest Real Estate Data (MRED), has been engaged in a legal battle with Zillow over whether the portal should be allowed to enforce its listing access standards in Chicagoland — and whether Compass will be allowed to put its listings on the portal.