If you have an online store or work for a marketing agency, you have probably already heard about CSS – Google’s Comparison Shopping Service. If you’re already handling Google Ads campaigns, you’re likely familiar with the topic. And if you’ve never heard of CSS, now is the time to learn how it can help you promote your business efficiently on the Google search engine.

Why do Comparison Shopping Services (CSS) exist?

We’ve all come across those special websites where we can compare product prices from different stores: these types of sites are called price comparison portals. Probably the most well-known portal in this category is Google Shopping.

To place Google Shopping ads (also known as “Product Listing Ads”), your company’s products need to be listed on such a price comparison portal (or multiple portals).

Until 2017, Google held a monopoly with its own price portal, Google Shopping, where it showcased Google Shopping Ads. This situation was deemed unfair, and some companies decided to take legal action against the famous search engine. Google’s monopolistic position was penalized by the court, resulting in Google losing the case and being compelled by the European Commission to launch the CSS – Comparison Shopping Services program.

Not all comparison portals are participating in this program. The CSS must be specially certified by Google and need to meet specific requirements.

All price comparison portals registered in the Google Comparison Shopping Services program and granted CSS partner status are allowed to place product ads for merchants in Google search results.

What’s the difference with Paid Ads?

How can you say that Google’s margin exists?

Here’s what Google says about its margin:

Google doesn’t specify exactly how much the margin is; it can only be calculated empirically after switching to a CSS provider based on results. From experience, this margin is about 20% of CPC. This is the famous discount promoted by CSS partners.

Why don’t you see directly in your account that you’re actually paying for Google’s CSS?

This is an internal decision by Google. The margin is deducted from the cost per click before your bid enters the auction. If you use Google Shopping CSS (the default one), your actual bid is approximately 20% lower than that of a merchant already working with another CSS portal (not Google CSS) and, therefore, is present with a bid 20% higher in the Google auction.

Of course, you only pay this margin to Google Shopping if someone clicks on the ad (if not, no margin is charged). But your bid in the Google auction is still about 20% lower each time.

Does a CSS Partner charge a fee for using their CSS?

Yes, most often it’s a monthly subscription. There are hundreds of CSS partners with a wide range of offerings. Many agencies choose to work with a particular CSS provider, and some even have their own CSS (for instance, Verteco Digital, a digital marketing agency, has its own CSS – Verteco Shop).

Will data in the feed be lost after migrating to another CSS? Will it ruin or change my marketing campaigns?

No. Migration from one CSS to another occurs internally between the CSS provider and Google. Google “connects” your Merchant Center account to a CSS account, and the Google margin is no longer deducted from CPC when ads enter the auction. If anything happens to the data (though it shouldn’t), it’s Google’s fault, not the CSS’s.

Does Google push down campaigns that are created using a different CSS?

No, Google doesn’t want to end up in court again and be penalized 😊

So, it all depends on how well you manage your marketing campaigns. With poorly targeted campaigns, not even Google Shopping as a CSS can help.

Google’s margin will no longer be charged. What happens to my budget?

You no longer pay Google’s margin, but, of course, Google won’t send the money back to your advertising budget. In reality, your bid is automatically 20% higher, and you can use your budget for Google ads much more effectively. It’s up to you how to manage your campaigns so that your strategy pays off. You can either keep the same budget and get more clicks on the ad or reduce the cost per click and maintain the same results while spending less.

In which countries is the Google CSS program available?

The program is available in 21 countries within and beyond the EU: Germany, Austria, Switzerland, Greece, Hungary, Ireland, Italy, Netherlands, Norway, Belgium, Czech Republic, Denmark, Finland, France, Poland, Portugal, Romania, Slovakia, Spain, Sweden, and the United Kingdom. So, essentially, EU countries, the UK, and Switzerland.

How can you use both an external CSS and Google CSS at the same time?

You can use two Merchant Center accounts. The first account is connected to Google Shopping. The second – to an external CSS.

How many CSS can you Use at the same time?

As many as you want.

What happens?

Nothing good. If you use multiple CSSs simultaneously, you won’t get greater coverage because Google prevents multiple listings of a provider’s ads.

From a performance perspective, this isn’t recommended. There are no advantages; in fact, there are even some disadvantages such as cannibalizing your own ads and having a weaker overall result.

How do CSS providers differ one from another?

There are three categories of CSS :

A Premium CSS Partner has more merchants registered as clients (only in terms of numbers). But it’s not always an advantage. A CSS provider with hundreds of clients outside of you won’t be able to handle you efficiently and won’t provide adequate support, especially in your native language. Verteco offers personalized support to all countries participating in the Verteco Shop program, with specially allocated managers, native speakers, who offer support and assistance efficiently.

Technically, there’s no difference between Participant, CSS Partner, and Premium CSS Partner. Google’s margin is not charged for any of them. But a CSS can offer additional services or manage your advertising campaigns.

It’s good to think about what exactly you need and how much it costs. There’s no point in paying for services just because they are offered by a large and well-known provider but also very expensive on the market. Practically, all external CSSs offer exactly the same thing. The size and age of the company guarantee superior quality services. Technically, all CSSs are the same; the differences are only aesthetic, in design, not functionality.


Google CSS providers give merchants a bidding advantage over competitors who aren’t yet using external CSS (except for Google Shopping CSS itself). It’s wise to choose a CSS for which you have all the necessary information and can test it as Verteco, for example, offers the possibility to use it for free for a month.

Get more info about verteco.shop CSS

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