Twelve European comparison shopping companies told the European Commission on 8 September 2026 that the remedy taking shape in the Google Shopping case risks entrenching the company it is meant to constrain, and asked Brussels to require Google Shopping to bid inside every rival unit.

In Short

A group of European price comparison companies wrote to the European Commission saying the fix Brussels is designing for Google Search could backfire. Their worry is that if Google gets its own shopping box and keeps rival inventory out of it, shops will go back to advertising through Google anyway just to stay visible. They want Google forced to compete inside everyone else's box too, and they want the whole thing tested on live search traffic before it is signed off.

A coalition draws one red line

The letter, addressed to Commission President Ursula von der Leyen, Executive Vice-President Teresa Ribera Rodríguez, Director-General for Competition Olivier Guersent and Thomas Kramler, head of the Digital Markets DMA unit at DG COMP, opens with support for enforcement and closes with a warning about how enforcement is being designed.

According to the coalition, regulatory discussions are moving toward a model for the paid Product Ads Unit in which competing comparison shopping services each display their own advertising unit inside Google Search. The letter calls this a "box-to-box" model. The signatories say they understand this is the direction of travel, and they set out their conditions for it without endorsing it. Their feedback, the letter states, is presented as a structural guardrail to mitigate market foreclosure rather than as validation of the architecture.

One condition is framed as absolute. A closed box operated by Google, in which merchant inventory submitted through competing services cannot appear, would in the coalition's assessment grant Google an advantage no rival could overcome. Retailers would be compelled to circle back to advertising through Google's own comparison shopping service simply to preserve visibility on the results page. The letter puts Google's current position in the sector at above 50%, an estimate it attributes to no external source, and argues that a closed box would push that share higher rather than lower.

The remedy the coalition asks for is participation rather than separation: Google Shopping bidding inside every box, including boxes operated by its competitors, as what the letter describes as a live-market safeguard against "kingmaking". Without that, the signatories argue, box-to-box becomes a stronger form of the behaviour Article 6(5) prohibits.

Dirk Verzijden, founder of ShopForward, described the same concern in a public post on LinkedIn announcing his signature. The principle of more players competing for visibility sounds positive, he wrote, adding that the details matter.

Who signed, and what the group claims to represent

Twelve names appear at the foot of the letter, signing on behalf of what it calls the CSS Group: Martin Corcoran of Productcaster, Alberto Baggio of Booncy, Ingmar Albert of adstrong, Michal Zielinski of Sembot, Sebastian Reischl of shopmos, Bernhard Benz of McDiscount, Ciaron Dunne of Genie Shopping, John Cave of Shoptimised, Wouter Veenboer of Producthero, Dirk Verzijden of ShopForward, Dirk Verburg of Shoparize and Jan Radanitsch of smec.

The coalition dates its own formation to 2025, describing itself as a direct response to proposed search layout changes that its members considered economically damaging. To support that position it commissioned independent data modelling across live search queries, work the letter credits with exposing how the proposals under discussion at the time would have concentrated the market further.

Four figures carry the claim to standing. Member companies generate more than 340 million euros in combined annual turnover. They employ more than 1,000 specialists across Europe. They support more than 93,000 active European merchants. And the group estimates that it accounts for 74% of all third-party comparison shopping clicks across the European Economic Area and the United Kingdom. That last number is presented as an estimate by the coalition itself, not as an audited figure, and no methodology accompanies it.

Business models inside the group are not uniform. Membership spans price comparison websites, software-as-a-service platforms and e-commerce marketing services, a spread that explains why several of the six principles later in the letter insist on neutrality between operating models rather than on a single preferred design.

What Brussels decided in July

The letter arrives inside a fixed compliance window. Acting under Article 6(5) of the Digital Markets Act, the European Commission adopted Decision C(2026) 5358 final in Case DMA.100193 on 23 July 2026, fining Alphabet 460 million euros for self-preferencing in Google Search alongside a separate 430 million euro penalty covering Google Play steering. The combined 890 million euro package came with a cease-and-desist order and a 60-day deadline to bring the conduct to an end.

The 153-page decision text names nine separate Alphabet services as ranked more favourably than comparable third-party offerings. Two of them sit directly under this letter: products intermediation through the paid product advertisement unit, and products intermediation through the free products unit. Recital 713 leaves the method of compliance to Alphabet and sketches two routes. One extends equal prominence to similar third-party services. The other removes the prominence given to Alphabet's own distinct services altogether.

The mechanics of the paid unit are already described in the decision, and they are the mechanics the coalition wants preserved and extended. Only comparison shopping services can bid, merchants remunerate the service of their choice, that service decides which offers to enter, billing runs on cost per click to the service, and Google Shopping competes in the same auctions. Read against the letter, the box-to-box proposal would break the last of those five conditions by giving Google an auction it does not have to share.

The decision also settled a point the coalition explicitly welcomes. Where third-party providers are required to become Alphabet business partners in order to receive equal prominence, the Commission held, that is not equal treatment. The letter adds a second welcome, for the finding that relegating third-party links to secondary comparison tabs or rich web results fails the equal treatment test.

Google has rejected the finding. Kent Walker, President of Global Affairs at Google and Alphabet, argued in July that compliance would force the removal of real-time pricing and availability data for hotels, flights and restaurants from European results, and the company said it was evaluating an appeal. In a September 2025 consultation response the company had already claimed European businesses lost up to 30% of online traffic since the obligations took effect.

The deadline does not read the same in every source

There is a discrepancy worth stating plainly. Verzijden's LinkedIn post gives the deadline as 25 September. PPC Land's reading of the decision text puts it at 21 September 2026, counted as 60 calendar days from the 23 July adoption date, while noting that the decision does not state its notification date on the face of the text. Since the 60 days run from notification rather than from adoption, both figures can be correct depending on when the document reached Alphabet. The open letter itself avoids the question, referring only to a recent non-compliance decision and a 60-day mandate.

Either way, the window closes this month, and periodic penalty payments of up to 5% of average daily worldwide turnover become available from the deadline until compliance. Those payments accrue rather than arriving as a single figure, and they require a further Commission decision before they activate.

Six principles, and a request count that does not add up

The letter proposes six tests against which any new layout can be measured.

The first asks that remedies eliminate gatekeeper self-preferencing by design without creating single-winner dynamics, and that no single player be allowed to dominate product carousels. The second asks for dedicated mechanisms letting comparison platforms build brand recognition and route traffic to their own sites, with Product Listing Ads pointing at comparison websites facing neither algorithmic nor financial discrimination against standard product listings.

The third concerns click paths. Where a comparison service chooses to send a shopper straight to a merchant product page, the letter argues, search features need to accommodate that choice; mandatory intermediary clicks add friction, raise retailer costs and reduce satisfaction. The fourth asks for neutrality across business models, with an explicit objection to granting structural privileges to specific historic litigants. The letter does not name the litigants it has in mind.

The fifth is the operational core of the document. No remedy is to be finalised without live market testing, with empirical evaluation during testing phases measuring visibility trends, third-party market share and merchant visibility, and with the resulting data shared transparently with the affected industry. The sixth extends Article 6(5) forward, asking that safeguards apply across AI-assisted overviews, agentic search and integrated checkout protocols to prevent what the letter calls instant disintermediation.

The calls to action section states three requests and then lists four bullet points, an internal inconsistency in the document as supplied. The four are: give Alphabet scope to implement remedies reflecting economic realities rather than legalistic advertising principles; evaluate any proposed layout against real-world outcomes, with explicit safeguards against a return to pre-2017 levels of Google Shopping dominance; involve the coalition directly in remedy design and live testing, since solutions built behind closed doors risk unforeseen failure; and state publicly that all emerging AI search surfaces fall within Article 6(5) obligations.

That last request is the one with the longest reach. AI Overviews are absent from the July decision, and Commission proposals on how the principles apply to them remain under discussion with no published timeline.

Why the argument keeps returning to layout

Comparison shopping has been the test case for European platform regulation for nearly a decade, and the pattern of objection is consistent. When Google set out more than 20 modifications to European search in November 2024, including new units for comparison sites in shopping, hotels and flights, a coalition of more than 20 European price comparison websites said within weeks that the changes did not comply. In March 2026, eighteen industry and consumer organisations pressed the Commission for a formal non-compliance decision before the two-year mark of its open proceedings. In February 2026, reporting indicated Google was preparing to test giving rival vertical search services more prominent placement in European results.

The commercial stakes behind that history are measurable. A Stockholm court held in July 2026 that the changes Google made in 2017 never ended the abuse the original decision identified, awarding Klarna Technologies principal damages of 950 million pounds for the United Kingdom alone. Travel bodies have made a parallel case, citing Google's share of European hotel search usage rising from 37% in 2013 to 80% in 2023.

For the merchants sitting underneath the comparison layer, the economics have been moving in one direction. Channable, which acquired Producthero in May 2025, reported that European e-commerce advertisers lost 46% of return on ad spend as clicks became more expensive across a twelve-month comparison ending in June 2026. Placement inside Google's own surfaces has meanwhile been expanding: sponsored tiles began appearing in the same display layer as free listings inside the Shopping tab in April 2026.

The sixth principle gains force from a September 2026 measurement. Productrise found that where the same product appeared in both AI Mode and conventional search on the same day, the lead price in AI Mode averaged 21.6% higher, with the lead seller differing on 49.6% of matched products and only 1.28% of traditional search products appearing in AI Mode at all. Two surfaces on the same domain are already drawing from what amounts to different catalogues. A remedy scoped to one of them regulates a shrinking share of the shopping journey.

What a box decides

For agencies and in-house teams running product feeds in Europe, the practical question is narrow and expensive. If Google's box accepts only inventory submitted through Google's own comparison service, feed strategy consolidates around a single intermediary, and the choice of intermediary that the current auction rewards stops carrying commercial weight. If Google Shopping is required to bid inside competing boxes, the auction described in the July decision survives with more operators inside it, and the sector the coalition represents keeps a route to the results page.

Neither outcome has been decided in public. The Commission has not published the layout under discussion, the coalition's account of the direction of travel is unverified from Brussels, and the letter is an advocacy document written by parties with a direct financial interest in the answer. What the letter does establish is that the group claiming the largest share of third-party comparison clicks in Europe considers the remedy under design capable of making its own position worse.

Timeline

Summary

Who: Twelve European comparison shopping companies signing as the CSS Group, including Productcaster, Booncy, adstrong, Sembot, shopmos, McDiscount, Genie Shopping, Shoptimised, Producthero, ShopForward, Shoparize and smec, writing to Commission President Ursula von der Leyen, Executive Vice-President Teresa Ribera Rodríguez, Director-General Olivier Guersent and DMA unit head Thomas Kramler.

What: An open letter warning that a box-to-box remedy allowing Google to operate a shopping unit closed to rival inventory would deepen rather than correct self-preferencing, paired with six evaluation principles and a demand that Google Shopping be required to bid inside every competing box.

When: Dated 8 September 2026, sent inside the 60-day compliance window opened by the Commission's 23 July 2026 non-compliance decision, with the deadline given as 21 September in the decision arithmetic and as 25 September by one signatory.

Where: Brussels, covering Google Search results across the European Economic Area, with the coalition's click-share estimate also spanning the United Kingdom.

Why: The signatories say they support more than 93,000 European merchants and account for an estimated 74% of third-party comparison shopping clicks, and they argue that a closed gatekeeper box would compel retailers to return to Google's own comparison service to preserve visibility, lifting a position they estimate at above 50% rather than opening the market Article 6(5) was written to contest.