The EU Antitrust Ruling That Created CSS
On June 27, 2017, the European Commission fined Google 2.42 billion EUR for systematically favouring its own comparison shopping service over competitors in search results. That single ruling created the entire CSS ecosystem that saves European merchants money on Google Shopping today.
The case, officially numbered AT.39740, remains one of the most consequential antitrust decisions in the history of European competition law. It fundamentally changed how Google Shopping operates in Europe and gave rise to the independent CSS partner program that companies like Cobiro now participate in. Understanding this ruling is essential for any merchant who wants to know why CSS exists and whether the advantage is likely to last.
What Google Did Wrong
The European Commission's finding was specific and well-documented. Google held a dominant position in general internet search across all EEA countries, with market shares consistently above 90%. Google used that dominance to give its own comparison shopping service (Google Shopping) an illegal advantage.
In practical terms, this meant that when a user searched for a product, Google displayed its own Shopping results prominently at the top of the page in a visually rich box format, while rival comparison shopping services were treated as generic web results and demoted through Google's ranking algorithms. The Commission found evidence that this was a deliberate strategy, not an incidental outcome of algorithmic relevance.
The result was devastating for competing comparison shopping services. The Commission documented traffic drops of up to 85% for some competitors on certain country-level domains. Meanwhile, Google Shopping's traffic increased by a factor of 45 in the UK between 2011 and 2016. This was not because Google Shopping offered a better product. It was because Google used its search dominance to funnel users away from competitors and toward its own service.
Key Fact
The 2.42 billion EUR fine was the largest antitrust fine in EU history at the time it was issued. It has since been surpassed by the 4.34 billion EUR fine Google received in the Android case (2018), but the Shopping case remains the one that most directly affects merchants running Google Shopping ads today.
The Full Timeline
The case did not happen overnight. It was the result of years of complaints, investigation, and legal proceedings. Here is the complete timeline:
2004 to 2010: Complaints Accumulate
From 2004 onward, comparison shopping services began noticing their traffic declining as Google increasingly promoted its own product search results. Foundem, a UK-based comparison shopping service, was among the first to file a formal complaint with the European Commission in 2009. Other comparison services, including Kelkoo and several national players, followed with their own complaints.
June 2010: EC Opens Formal Investigation
The European Commission officially opened an antitrust investigation into Google's treatment of comparison shopping services. This triggered a formal process that would take seven years to reach a decision.
November 2010: Statement of Objections
The Commission sent Google a formal statement of objections, outlining its preliminary view that Google had abused its dominant position. Google proposed several sets of commitments to resolve the case, but the Commission ultimately rejected all of them as insufficient.
June 27, 2017: The Decision
After seven years of investigation, the Commission issued its final decision. Google was found to have infringed Article 102 of the Treaty on the Functioning of the European Union (abuse of dominant position). The fine was set at 2,424,495,000 EUR. Google was ordered to comply with the decision within 90 days or face penalty payments of up to 5% of Alphabet's average daily worldwide turnover.
September 2017: Google Implements the Remedy
Google chose to comply by creating a mechanism that would give rival comparison shopping services equal access to the Shopping auction. Google Shopping Europe (GSE) was established as a separate business unit that would compete with independent CSS providers on equal terms. The CSS partner program officially launched, and for the first time, merchants could choose which CSS submitted their Shopping ads.
This is the moment that matters most for merchants. The creation of the CSS program meant that independent providers like Cobiro could submit Shopping ads on behalf of merchants without the approximately 20% margin that GSE applies. The practical effect: merchants who switch to an independent CSS pay less per click for the same ad placements.
November 2021: General Court Upholds the Decision
Google appealed the Commission's decision to the General Court of the European Union (case T-612/17). On November 10, 2021, the General Court upheld the Commission's finding in almost all respects. The court confirmed that Google had abused its dominant position and that the fine was justified. The court reduced the fine marginally on procedural grounds but the substance of the ruling stood.
September 2024: CJEU Final Appeal Dismissed
Google took its final appeal to the Court of Justice of the European Union (CJEU), the highest court in the EU legal system. In September 2024, the CJEU dismissed Google's appeal, confirming the General Court's judgment. This closed all avenues for further appeal within the EU legal system. The ruling is now final and cannot be overturned.
Important Context
The CSS advantage exists solely because of this ruling. If Google's appeals had succeeded, the Commission's remedy could have been reversed and the CSS program could have been discontinued. With the CJEU's final dismissal in September 2024, that risk is now eliminated. The legal foundation for CSS is settled.
How the Remedy Works in Practice
Google's compliance mechanism works as follows. Google Shopping Europe operates as a separate entity that must fund itself commercially. To do so, it applies a margin to the bids it submits on behalf of merchants. This margin is approximately 20% of the CPC.
Independent CSS partners, by contrast, do not carry this margin. When an independent CSS submits a bid, the full bid amount goes into the auction. There is no intermediary margin deducted. This means that for any given bid, a merchant using an independent CSS gets more competitive placement, or can achieve the same placement at a lower cost.
The European Commission monitors Google's compliance on an ongoing basis. Google is required to submit regular reports demonstrating that independent CSS partners receive equal treatment in terms of auction mechanics, ad placements, and data access. Any deviation from equal treatment could trigger additional penalties.
Impact on Merchants
Before 2017, European merchants had no choice. All Shopping ads were submitted through Google Shopping, and the margin was invisible because there was no alternative to compare against. Merchants simply accepted their CPCs as the cost of doing business.
After the ruling, every European merchant gained the ability to choose their CSS partner. The practical impact is significant: merchants who switch from GSE to an independent CSS like Cobiro typically see CPC reductions of 15% to 20%, with no change to their campaigns, product data, or ad placements.
Despite this clear advantage, a large proportion of European merchants remain on GSE, often because they are simply unaware that alternatives exist. This is one of the reasons educational resources like this hub exist: to help merchants understand the option they have and make an informed choice.
Tip
If you are spending more than 200 EUR per month on Google Shopping in any EEA country, the UK, or Switzerland, switching to an independent CSS is almost certainly worth it. The savings from reduced CPCs will outweigh the CSS provider's fee within the first month for most merchants. See our savings calculator for a concrete estimate.
Looking Ahead
With the CJEU's final ruling in 2024, the legal underpinning of the CSS program is settled. The European Commission continues to monitor Google's compliance, and the Digital Markets Act (DMA), which came into force in 2023, provides additional regulatory oversight for Google as a designated "gatekeeper" platform.
For merchants, this means the CSS advantage is not a temporary loophole. It is a structural feature of how Google Shopping operates in Europe, backed by law and ongoing regulatory enforcement. If anything, the DMA may lead to further pro-competitive measures in the future.
In the next article, we look at how CSS works from a technical perspective, including the Merchant Center architecture, auction mechanics, and the practical steps involved in switching.