A coalition representing more than 93,000 European merchants has written to the European Commission warning that Google's proposed fix for its antitrust problem could push retailers back into Google's own shopping service. The CSS Group's letter landed ahead of a September 25 compliance deadline, and the specific concern is that merchants using independent comparison shopping services could lose access to Google's shopping box entirely.

If you advertise products in the EU or UK, the CSS you use is likely saving you roughly 20% on cost-per-click. That's the arrangement now in question.

Why CSS Exists in the First Place

Some background matters here, because the CSS system is a regulatory artifact rather than a product Google built voluntarily.

The European Commission ruled in 2017 that Google had illegally favored its own shopping service in search results. The remedy was the CSS Partner Program: merchants in supported European markets must work with at least one comparison shopping service to place Shopping ads or free product listings. Independent CSS providers compete in the same auction Google's own service does, and the rebate structure typically translates to meaningfully lower CPCs for merchants who use one.

The program grew into real infrastructure. More than 600,000 merchants across the EEA and UK now work with a CSS, up 48% since 2021, across roughly 1,550 CSS websites.

What's Happening Now

In July, the Commission fined Google €460 million after finding the company favored its own services across shopping, hotel, transport, and sports results. Google got 60 days to propose a compliant approach or face periodic penalty payments. According to the CSS signatories, that window closes September 25.

Discussions reportedly include letting comparison shopping services compete for their own product boxes. The coalition's objection is that depending on how Google designs this, merchants whose inventory sits with an independent CSS could find that inventory excluded from Google's own shopping box, which is where most of the visibility lives.

Google has separately warned that broader changes to European search results would hurt user experience and raise business costs, confirming an overhaul is coming without clarifying the Shopping specifics.

What's Confirmed and What Isn't

The coalition's letter is real, the €460 million fine is real, and the September 25 deadline is real. The exclusion scenario is not. It's a possible design outcome the coalition is warning against, not an announced Google policy.

That distinction matters for how much attention to give this right now. The coalition is asking for live-market testing and transparent competition data before any permanent model gets adopted, and it wants equivalent protections extended to AI Overviews, AI Mode, and agentic shopping experiences. Those requests suggest the group sees the current design discussions as unfinished rather than settled.

Why the AI Angle Is the Part Worth Tracking

The coalition's push to cover AI Overviews and agentic shopping is the forward-looking piece of this. Whatever structure Google adopts for Shopping in Europe will likely become the template for how products surface in AI-driven search results there.

That connects directly to a pattern running across every major platform right now. Google has already started letting its AI rewrite product titles in Shopping ads when it decides a seller's original title isn't the best match. If product visibility in AI surfaces gets decided by the same structure being negotiated now, the CSS question stops being about CPC savings and becomes about whether independent providers can reach AI shopping results at all.

What to Do

Nothing requires action before September 25, since no final design exists. But if you sell in Europe through a CSS, this is worth a conversation with your provider about what they're hearing and what contingencies they're planning.

More practically, know what your CSS arrangement is actually worth to you. If you've never calculated the CPC difference between your current setup and advertising directly through Google Shopping, that number is the size of your exposure if the arrangement changes. Sellers who can quantify it will make faster decisions than those discovering the gap after the fact.