Zillow’s recent confrontation with MLS-hosted “private listings” in Chicago represents more than a regional policy shift. It’s a signal that the nation’s largest real estate portal is transitioning from participant to policymaker.
From Broker to Rule-Maker
Zillow’s new “Listing Access Standards” redefine what “public” means in the listing world, dictating when properties can be shared and who gets visibility.
That’s not a competitive adjustment, it’s a governance maneuver. Zillow is moving beyond brokerage operations and into industry rule-setting.
Following the Platform Playbook
This strategic evolution mirrors the path of other dominant platforms that reshaped their industries by writing their own rules:
- Amazon controls pricing, presentation, and fulfillment, enforcing compliance through the Buy Box.
- Airbnb dictates refund, cleaning, and safety standards globally, often superseding local regulation.
- Uber governs driver pay models, pricing, and safety criteria, effectively regulating mobility markets.
- Google and Apple decide who gets seen, who gets paid, and what content qualifies as legitimate.
Zillow’s influence now functions the same way, becoming a de facto regulator of real estate visibility, using its consumer reach as the enforcement mechanism.
The ChatGPT App: A Quiet Policy Leap
Earlier this year, Zillow launched a ChatGPT app that lets consumers browse active MLS listings directly within chatgpt.com. They “self approved” putting listings on ChatGPT.com and the ChatGPT App. ChatGPT.com is clearly not Zillow’s website and the ChatGPT app and browser are clearly not Zillow’s app or browser.
The technical innovation is impressive, but the governance decision is more revealing. Zillow did not seek formal MLS approval to display listings on a third-party domain. Instead, it interpreted its IDX data license as permitting distribution “to any consumer-facing environment” they choose regardless of control. Moreover, they entered into a license agreement with ChatGPT that the MLS is not included in. That is the definition of third party distribution.
That unilateral move expanded the display boundary of MLS data and set a precedent, platform integration now equals policy creation. Trust me, other brokers are working on similar moves, and this precedent setting by accepting Zillow’s behavior will make it impossible to prevent other brokers from similar expansion of display boundaries. Very soon, you will see brokers putting their search solutions on newspaper and other community websites and snagging all of the leads using the listings of every other firm in the market.
It’s the same pattern we’ve seen before:
- Amazon extended seller data to Alexa without supplier consent.
- Airbnb syndicated listings into Google Travel before host opt-in.
- Uber integrated public-transit data long before city agencies approved it.
Zillow’s ChatGPT rollout fits perfectly into that lineage: “innovation first, permission later.”
Legal Flashpoint: Compass Raises Antitrust and Collusion Claims
This newfound assertiveness hasn’t gone unnoticed. Compass has filed antitrust and collusion claims against Zillow, alleging that its dual role as both broker and marketplace creates an unfair competitive advantage.
Compass contends that Zillow leverages its control over listing visibility to favor its own brokerage operations and preferred partners, using “policy” language to justify competitive exclusion.
If true, this behavior parallels the controversies that engulfed other platform giants:
- Amazon faced EU scrutiny for prioritizing private-label products.
- Apple confronted regulators for App Store self-preferencing.
- Google continues to battle antitrust suits for privileging its ad services.
Compass’s action could become a defining case for platform power in real estate, testing whether a portal can simultaneously compete and regulate.
Regardless of outcome, it underscores a central tension, when the same entity controls both traffic and rules, traditional competition boundaries collapse.
Implications for MLSs and Brokerages
- MLSs now face a legitimacy test. If a private portal can redefine data display and access unilaterally, who truly governs the marketplace?
- Brokerages must navigate dual compliance regimes, MLS rules versus portal rules.
- Technology vendors risk conflicts as Zillow’s integrations stretch beyond traditional IDX boundaries.
- Consumers may gain transparency yet lose control over how listings are marketed or prioritized when the listing agent no longer has control over the listing.
Zillow’s messaging, “equal access for buyers and sellers,” echoes the trust-and-safety rationale other platforms used while consolidating dominance. Beneath the consumer-first language lies a power shift toward centralized control of visibility.
A New Era: Portal Governance
If Zillow enforces compliance through visibility, boosting listings that follow its standards and suppressing those that don’t, it effectively becomes the arbiter of participation.
That’s no longer competition, that’s governance through algorithmic enforcement.
WAV Group Analysis
Zillow is moving from data sharing to data control, a trajectory pioneered by Amazon, Airbnb, and Uber. The company’s new Listing Access Standards, its ChatGPT integration, and now the Compass lawsuit all signal the dawn of what WAV Group identifies as “Portal Governance.”
For MLS and brokerage leaders, the strategic imperatives are clear:
- Audit listing policies for conflicts with emerging portal requirements.
- Engage in direct governance dialogue with major platforms rather than reactive compliance.
- Prepare communications strategies explaining visibility, data control, and consumer transparency.
The next decade will determine whether MLSs remain the backbone of cooperation, or evolve into data providers to platforms that make their own rules.
If you are a broker or agent who thinks that the Zillow ChatGPT integration is outside of the IDX program and should be terminated, here is what an MLS exec told me you should do:
Ask the following questions of your MLS or file a professional conduct claim against Zillow with your association.
- Is the domain “ChatGPT.com” Zillow’s domain? The data license agreement says that you may only display search on the domain that you yours or under your control.
- It’s not partial. It’s fully under your control. You can’t just control a little piece. It’s fully under your control.
- Is the ChatGPT app Zillow’s app? Same thing here. The rules state that the app must be yours. Is this ChatGPTs app with Zillow running inside?
- Is the app hosted by Zillow or ChatGPT? You will need a programmer to answer this.
- Is Zillow providing an API data feed (derivative product) to Bing (third party) that is syndicated to ChatGPT? This is a separate issue – but part of the same problem.
- Is this reciprocal?
- Is Zillow providing New Home, Rentals, and FSBO listings listed with Zillow to the MLS for the mutual benefits of market making with other brokers?
WAV Group Perspective:
Zillow isn’t just adopting innovation, it’s adopting authority. The question for the industry is no longer whether portals will shape policy, but how MLSs and brokers will respond when they do. Zillow is valued at over USD$17 Billion by shareholders who, like us, think that they are going to dramatically profit from their position as a leader in the real estate industry.
Today, Zillow is clearly the most impressive company in real estate with Compass coming in second. MLSs and Associations need to recenter themselves as the core of the real estate industry or they may find their relevance deteriorate faster than expected.
