The EU Ruling Behind CSS (AT.39740): Why Google Must Offer It

The short version

In June 2017, the European Commission concluded a multi-year investigation and ruled that Google had abused its dominance as a search engine by giving its own comparison shopping service, Google Shopping, an illegal advantage over competing services. The Commission fined Google €2.42 billion, the largest competition fine it had imposed at that point, and required Google to treat rival Comparison Shopping Services equally. That equal-treatment requirement is what makes third-party CSS access, and the CPC saving that comes with it, possible.

What Google actually did

The investigation centred on how Google presented shopping results in its general search engine. The Commission found that Google had systematically given prominent placement to its own comparison shopping service while demoting competing comparison services in its search results.

In practice, this meant that when people searched for products, Google's own Shopping results appeared in prime positions, while rival comparison shopping sites were pushed far down the rankings where they received little traffic. Because Google held a dominant position in general search across Europe, this self-preferencing had a large effect on which services consumers saw and used.

The Commission concluded this was an abuse of Google's dominant market position under EU competition law.

The decision: 27 June 2017, case AT.39740

On 27 June 2017, after a formal investigation that ran for several years, the European Commission adopted its decision in case AT.39740. The findings were:

• Google held a dominant position in general internet search in the European Economic Area.
• Google had abused that dominance by favouring its own comparison shopping service over competitors in its search results.
• The conduct breached EU competition rules.

The Commission imposed a fine of €2.42 billion. At the time, it was the highest fine the Commission had ever levied for a competition law breach.

Crucially, the decision did not stop at a fine. It required Google to bring the infringement to an end and to treat competing comparison shopping services equally to its own.

The remedy: equal treatment, and how CSS works

The remedy is the part that matters for advertisers. Google was required to give rival comparison shopping services access to the Shopping auction on equal terms with its own service.

This is the legal foundation of the modern CSS programme. An authorised Comparison Shopping Service can submit product listings to Google Shopping on behalf of merchants, and those listings compete in the same auction that Google's own Shopping uses, on equal terms.

The roughly 20% lower cost-per-click that merchants see through an authorised CSS flows directly from this equal-access structure. When ads run through Google's own Shopping service, a margin is taken before the bid enters the auction. When they run through an authorised CSS, the full bid enters the auction directly. Equal access is what removes that margin, and the regulation is what guarantees equal access.

The appeals: upheld, not overturned

Google did not accept the decision quietly. It appealed.

The case worked its way through the EU court system. The General Court of the European Union largely upheld the Commission's decision in 2021, dismissing Google's appeal in substance and confirming the finding of abuse.

Google appealed again to the Court of Justice of the European Union, the EU's highest court. In 2024, the Court of Justice dismissed Google's final appeal and confirmed the Commission's decision and the €2.42 billion fine. That brought the case to a definitive close at the highest judicial level.

In other words, this is not an open dispute or a theory. It is settled law, confirmed through the EU's full appeals process up to its highest court.

Why this matters for your Shopping costs

The chain is simple:

1. The Commission found Google abused its dominance and ordered equal access for rival CSS providers (2017, AT.39740). 2. The EU courts upheld that decision, with the Court of Justice confirming it in 2024. 3. Equal access means an authorised CSS can put your full bid into the Shopping auction directly. 4. That direct access is what produces the roughly 20% lower cost-per-click.

So the saving is not a promotion that can be withdrawn at a marketing department's whim. It is a structural feature created by EU competition enforcement and protected by a final court ruling. As long as Google operates Shopping in Europe, authorised CSS providers have the legal right to participate on equal terms.

Is the saving safe long-term?

This is the natural question, and the legal record is reassuring. The obligation on Google to offer equal access has survived Google's own appeals all the way to the Court of Justice of the EU and was confirmed in 2024. The structural requirement is in active operation across the European CSS markets. Programme details can evolve over time, as any regulated framework can, but the underlying requirement to offer CSS access has been tested in court and upheld.

The bottom line

Your CSS saving rests on one of the most significant competition rulings in EU history. The Commission found Google abused its dominance, fined it €2.42 billion, and ordered equal access for rival comparison shopping services in case AT.39740 on 27 June 2017. The EU courts upheld that decision, with final confirmation by the Court of Justice in 2024. The roughly 20% lower cost-per-click you get through an authorised CSS is the direct, regulated result of that ruling.

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