In the fast-paced world of ecommerce, marketing leaders face a constant battle: rising advertising costs. Year after year, CPC (Cost Per Click) continues to increase, and competition in Google auctions becomes increasingly fierce. To maintain ROAS (Return on Ad Spend), we optimize feeds, adjust creatives and refine audiences.

But what if I told you there is a structural inefficiency in your account that is costing you 20% of purchasing power in every single auction?

It’s not a configuration error or a bad practice. It’s the standard way Google Shopping operates in Europe. And the solution to correct it is not technical — it’s strategic.

If you manage an online store in Europe, chances are you’re leaving money on the table. Literally. While you bid €1.00 for a click on your product ads, competitors using that same euro may be achieving significantly greater visibility.

The trick? It’s not a trick. It’s a strategic decision called Google CSS. And surprisingly, many ecommerce businesses are still not taking advantage of it.

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What is Google CSS and why should you care?

To understand it, we need to go back to 2017. That year, the European Commission fined Google for favoring its own price comparison service in search results. Google’s solution to avoid further penalties was to open up the ecosystem: it allowed other Comparison Shopping Services (CSS) to compete in the same ad auction.

Today, when you see an ad in the Shopping tab, you will notice a label that says "By Google" or "By [Comparison Partner Name]". That small line of text can make the difference between being efficient or wasting budget.

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The 20% rule: The real competitive advantage

This is where it gets interesting. To ensure fair competition, Google separates part of its own operation. When you use the standard service (Google Shopping), they retain approximately 20% of your bid as margin before you enter the auction.

Quick example:

  • With Google Shopping: You bid €1.00 → You pay €1.00. Google retains ~€0.20 as margin. Only €0.80 enters the auction.
  • With a CSS Partner (such as Adsmurai): You pay €1.00. The CSS partner does not apply that Google margin adjustment. The full €1.00 enters the auction.

By switching to a CSS Partner, your same investment gains 25% more effective power (moving from €0.80 to €1.00 represents a 25% increase). This allows you to win positions you previously lost to competitors using an external CSS, or maintain your current position while paying less (lower CPC).

Switching to a CSS does not mean leaving Google Ads or losing control of your campaigns. It simply changes the “channel” through which your data is submitted to Google.

This is where Adsmurai, as a certified CSS Partner, turns this theoretical advantage into tangible value for brands. By migrating your Merchant Center to our CSS, we activate that immediate efficiency gain.

 

What changes and what stays the same?

Many advertisers worry that “touching” Merchant Center could destabilize their campaigns. The reality is much simpler:

  • What changes:
    1. The ad label: Instead of saying “By Google”, your product listings will show “By Adsmurai”.
    2. Efficiency: Your bids enter the auction without the margin adjustment.
  • What does NOT change:
    1. Your campaigns: They continue to be managed from your usual Google Ads account.
    2. Traffic: All traffic continues to be directed to your website.
    3. Data: You keep your historical data and metrics.
    4. Cost: For Adsmurai clients, this service is free of charge.

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How Google CSS impacts your brand’s growth

The benefit of CSS is not just paying less per click. Having around 20% more competitiveness in the auction creates positive ripple effects:

  • Higher Impression Share

Your ad can enter auctions where it previously did not qualify because your net bid was too low.
Result: more presence in relevant searches without increasing your budget.

  • Better positioning

By competing more strongly, your products can appear in more visible positions within Shopping. Greater visibility typically leads to higher CTR and therefore more qualified traffic.

  • Greater stability in competitive categories

In sectors with high CPCs and strong competition, this structural advantage helps you maintain positions without continuously increasing investment.

  • Greater scalability

If you decide to increase your budget, you do so from a more efficient baseline. You are not starting from a disadvantage.

 

In which countries does Google CSS apply?

The Google CSS program is active in:

Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Spain, Sweden, Switzerland and the United Kingdom.

If you operate in any of these markets, you can benefit from the program.

How to activate the change (without headaches)

The migration is an administrative process that does not require development hours or complex integrations. At Adsmurai, we have simplified it as much as possible:

  1. Request: You provide your Google Merchant Center ID.
  2. Connection: We send an official request through Google’s platform.
  3. Approval: You approve the request from your control panel.
  4. Activation: Immediately, your account begins operating under Adsmurai’s CSS and starts benefiting from the auction advantage.

The market has changed

The Google Shopping ecosystem in Europe is no longer a monopoly. Continuing to use Google’s default CSS is, in most cases, paying a “convenience tax” that more agile competitors have already eliminated.

Want to know if your account is eligible for this change or need recommendations on reliable partners? We can help you calculate your potential savings if you share an approximate figure of your monthly Shopping investment.

 


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