Operators of price comparison portals in the European Economic Area (EEA) and Switzerland can place shopping ads on Google on behalf of merchants. The advantage for the merchant: 20% savings on the click prices.

In this article you will learn everything important about Google Shopping CSS.

Google Shopping CSS represents the biggest change to Google Shopping in recent years. As CSS partners gain the benefit of a 20% margin advantage, it should be clear that more and more online retailers will rely on the Google Shopping CSS Ads topic in the future. As a result, the proportion of Google Shopping search results that are set by price comparison sites is likely to continue to rise over time.

As is so often the case in e-commerce, those who are quick and seize existing opportunities early will benefit. Those who become active with Google CSS now have the advantage of being able to outpace their own competitors thanks to the margin advantage of 20%.

What is Google Shopping CSS?

Google Shopping CSS is a way to display shopping ads. CSS stands for Comparison Shopping Services and concerns the main search on the Google homepage. The introduction of Google Shopping CSS became necessary because Google was using the search results page exclusively for its own offer: Google Shopping. Other price comparisons (Comparison Shopping Services) only appeared much further down in the search results. The European Commission found this to be unfair competition.

In order to create a level playing field, Google rebranded the ad platform as Google Shopping Europe (GSE) and opened it up to external price comparison sites, the Google CSS partners. The result: for some time now, all Shopping ads that appear in Google’s main search results have been part of a Comparison Shopping Service (CSS).

Google Shopping itself also acts as a CSS („From Google“), participates in the bidding auction like the other price comparison platforms, and competes with other CSSs that place bids on behalf of merchants. However, in order to use its own price comparison in an EU-compliant manner, Google retains around 20% of your maxCPC bid as a margin. This means that your bids will always be reduced by about 20% if you leave them with Google Shopping Europe. If you use a CSS partner for your ads, the margin does not apply at all.

For Google users the difference is hardly noticeable, the only visible change is the added line „From ….“ at the bottom of the ad.

Why did Google Shoppping CSS become necessary?

The EU Commission’s accusation: Competition in the price comparison markets was restricted by the Google Shopping service. Google had exploited its monopoly position as a search engine by ranking its own Shopping ads disproportionately favorably. In plain language, this means that if a consumer is interested in a particular product and searches for it via the Google search engine, it is noticeable that Google Shopping ads are much more visible in the search results than other price comparison services. Google thus gives its own price comparison service a considerable advantage by placing its competitors in a worse position.

According to the Commission’s ruling, operators of price comparison portals in the European Economic Area (EEA) and Switzerland can place Shopping ads on Google on behalf of merchants.

20% lower CPCs on Google Shopping

At UnitedAds we pass on the margin that Google credits to the price comparisons completely to our customers. This means for you: With UnitedAds as a Google CSS partner, your click costs on Google Shopping will be around 20% lower.

In other words, your costs for Google Shopping will decrease by 20% or you will receive 20% more clicks for the same budget.

However, this only applies to the display of ads on the start page of Google Search: from the European Commission’s point of view, the „Shopping“ page is considered a stand-alone price comparison and is therefore not affected by the ruling.

What has changed through Google Shopping CSS?

For Google users, the introduction of Google Shopping CSS is hardly noticeable – the only visible change for now was the added line „From ….“ at the bottom of the ad. In the meantime, Google has launched its own ad format for CSS: the Comparison Listing Ads. They feature a second carousel alongside the normal Shopping Ads, highlighting all relevant price comparisons.

Advertisers, of course, the price of a click is the key change brought about by Google Shopping CSS. More specifically, the composition of merchant bids in Google Shopping has changed. Google Shopping retains about 20% of the bids as margin. For you as a merchant, this means that your bids are reduced by about 20% in the auction for the ad rank! So suddenly you are at a massive disadvantage compared to advertisers who already place their Google Shopping ads via a Google CSS partner.


Suppose you place a maxCPC bid of 1€. If you do not use CSS yet, but continue to use Google Shopping Europe (GSE), 0.20€ will be deducted from this bid. As a result, you enter the auction with the reduced bid of 0,80€.

If you do not advertise your products via GSE, but via another Google CSS partner, this margin will not apply. Your bids go into the auction with the full amount, i.e. 1€. The advantage: You win significantly more auctions with the same maxCPC bid and you can increase your traffic significantly or reduce the costs.

Google Shopping CSS Integration: Full Switch or Association

To play Google Shopping ads through a CSS partner, there are two ways to switch a previous GSE account to CSS. Advertisers must choose between Full Switch and the Association model.

With the Full Switch, an advertiser’s Merchant Center Account (MCA) is fully integrated with the CSS partner’s Multi Client Merchant Center (MCC). There are some technical aspects to consider when making this move. For example, if only a sub-account is moved rather than the full MCA, access rights may be lost during the move. A positive aspect of the full switch is that the CSS partner has insight into the product data, can identify the causes of problems himself, and there is transparency with a percentage-based payment model. However, the dependency of the advertiser on the CSS partner is higher than with the simple linking according to the association model and requires trust between both parties.

If an advertiser chooses the Association Model, its MCA is linked to the CSS partner in a relatively straightforward manner. In this case, the advertiser’s setting can remain unchanged, and the effort required to move is minimal – in fact, all that is needed is an email from the CSS partner to Google requesting the switch. If only a sub-account from an MCA is switched, the same risks of loss of access rights apply as with the Full Switch. The advantages of the full switch method just mentioned (full access and insight into the product data by the CSS partner) do not come into play here straight away. However, the CSS partner can be given access to the customer account or data feed via appropriate user invitations or by setting up an API interface.

In terms of handling and cooperation, Full Switch and Association hardly differ. It is more a question of trust, control and flexibility whether an advertiser moves its entire account to the CSS partner’s MCC or „docks“ via Association. Another method is to create a CSS subaccount: Opening a subaccount directly with a CSS price comparator is a good idea if you want to work with more than one CSS price comparator. This does not require any verification from Google. Nevertheless, the product links must lead to the target address in the webshop stored in the subaccount.

How to use Google Shopping CSS for your online store

If you want to use CSS via UnitedAds as a Google CSS partner, we will take care of all the formalities. We will submit an application for the activation of your Merchant Center Account (MCA).

There is practically no migration effort for you – everything remains the same. You can continue to work immediately, without the stress of moving and getting used to the new system.

Is it worthwhile switching to a Google CSS partner?

With minimal effort, your click costs are reduced by 20%. This makes the switch to a CSS partner worthwhile for any online store that invests more than around $1,000 budget in the Google Shopping marketing channel.

While the lifespan of Google Shopping CSS was still unclear at the beginning of the program, there is now much to suggest that it will remain a fixed component of Google Shopping. The pressure from the EU on Google continues to increase. The fact that Google Shopping Europe is still represented significantly more often in the search results than CSS Partners shows that there is still room for improvement. So Google will continue to motivate other price comparisons to be present in the Shopping ads. Google does this, for example, by developing formats such as Comparison Listing Ads (CLA), which are specifically intended for Google Shopping CSS Partners.

Those who still rely on Google Shopping Europe due to uncertainty should look into CSS now at the latest. However, the frequency and short notice with which Google informs about changes to the CSS program remains a challenge. Personal initiative and foresight on the part of CSS providers and advertisers are required in order to be successful with Google Shopping CSS in the future.

Dual Strategy Google Shopping Europe and Google Shopping CSS

CSS Shopping opened up new strategic playgrounds for advertisers. Companies were faced with the decision of shifting their entire budget to CSS Shopping, running GSE and CSS in parallel, or not using CSS at all.

As before, many online stores do not take advantage of CSS. This is probably mainly due to the many smaller merchants for whom CSS usage is not worthwhile because CSS fixed costs outweigh the savings that depend on the mediaspend. However, some advertisers run parallel campaigns across CSS and GSE. The disadvantage of this hybrid strategy is that the identical campaigns have to be maintained in two different Google Ads accounts.

There is no generally valid recommendation. The benefit of CSS Shopping depends not only on the amount of money invested, but also on the advertiser’s strategy. For example, those who want to displace their competitors can feed their ads into the auction via GSE and several CSS at the same time, thus generating high advertising pressure. Those who optimize for efficiency, on the other hand, should rely exclusively on CSS.