House prices are falling, sellers are running and against this backdrop the real estate advertising portals, Domain and REA Group, are each claiming the other is guilty of misleading the public with unsubstantiated claims about their market share and advertising impact.
Home sellers can spend tens of thousands of dollars with these advertising portals, so the outcome of the just-lodged legal claims is significant to all property sellers and would-be buyers.
Thereโs long been a bitter rivalry between the two property portals that cover most of the listings in the Australian housing market. They have worn a path between their head offices to the Federal Court.
REA Group (majority owned by News Corp) sued Domain (previously majority owned by this mastheadโs owner, Nine) in 2017 over advertising claims that Domain was the โ#1 property appโ and had โthe most property listings in Sydneyโ. The judge ruled in a split decision, deeming most of the competing superlative claims as โjust advertising pufferyโ.
There was the 2024 case where REA sued Domain over claims that Domain systematically scraped images, schematics, and floor plans for 181 listings without permission to use on its analytics service. That one was settled.
And last year the competition regulator had REAโs pricing in its sights after complaints about market power and pricing.
But having spent $3 billion last year to buy the Domain portal from Nine Entertainment, its new owner CoStar and founder Andy Florence are bringing his well-honed fighting skills to the Murdoch controlled but (much) larger REA, which trades as realestate.com.
Both portals will be facing some recent pressure as increasingly vendors are standing on the sidelines as prices are falling. There was a 7.0 per cent drop in auction activity last week from the previous week and it was 14.5 per cent below the same week a year ago.
The real estate portal barney has now landed in the Federal Court thanks to Domainโs legal claim that REA has misled the market with advertising claims that it found buyers for nine in every 10 properties listed on its site.
REA says this statement relies on internal modelling, citing what it calls its buyer impact model, which was informed by its internal data specialist PropTrack, which analysed more than 1 million properties sold between August 2023 and November 2025, drawing on billions of user interactions.
It said its modelling methodology has been given a tick by Deloitte, marking โthe first independently verified property buyer impact claim of its kind in the Australian marketโ.
In a tit-for-tat, Domain, which disputes the bona fides of the REA modelling, has become the subject of a cross-claim from REA which is alleging Domain is misleading the market about the success of its own platform.
Domain argues that REAโs contention that it attracts and engages the buyer for nine in 10 properties that sell on its platform doesnโt account for people who saw the same property for sale on the Domain portal.
And if REAโs representations amount to a claim that it has 90 per cent market share, Domain argues that it would infer to sellers that they only need to use one advertising platform.
Domain doesnโt think that REAโs model is able to identify that the actual buyer of a listed property was attracted to that property because they saw it on REAโs platform.
Domain doesnโt think the methodology can support the claim and that instead, the buyer impact model uses probability of user behaviour and engagement patterns, without verifying that those users were in fact the purchaser of the relevant property.
And if Domain used the same methodology, maybe it would come up with a nine in 10 claim.
REA is standing by its methodology and its claims, which analysed 10 million consumer data points.
A Federal Court judge will have the pleasure of wading through that one.
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