For quite a while now our support team has been bombarded with questions like “How does the CSS work when the P.Max campaigns have assets” and “We can’t see the results of the CSS”?

We always speak the truth and for the whole time since the P.Max ads went online, we have been working on bringing some clarity to the whole situation.

By teaming up with Czech Marketing Agency Better and their client we managed to find out what is the difference between the campaigns by mankind parallel campaigns with the same settings.

logo of Better Marketing

Better Marketing is a full-service online advertising agency operating in the Czech Republic since 2005. At present, the company consists of 40 employees, who are available to clients not only in Prague and Brno but almost in the whole Czech Republic.

Since 2006, they have been certified by Google Inc. and hold a Google Qualified Company certificate. They are a member of the AKA (Association of Communication Agencies).

logo of is a well-known manufacturer of sports, construction, and overall industry equipment. The whole manufacture is based in Germany and the Czech Republic. They are holders of ISO 9001 and ISO 14001 certificates as well as the IATF 16949 certificate. In one word they are your trusty supplier for sports and protective nets, mats, rope courses, and sports structures.

The problem – Measurement of the overall impact of Shopping in EU CSS

As we said before, we had an issue where we couldn’t realistically show the CSS results on P.Max campaigns that had assets filled and advertised outside the Shopping and Dynamic remarketing ads.

For this issue, Marketing Agency Better came to our salvation with client Berger-Huck who wanted to compare the results of campaigns that run simultaneously from two different Google Merchant Centers.

The Better Agency set up the campaigns with the same budgets, settings, and products and put them online and against each other. If you follow our blogposts we have done something similar with Smart Shopping Ads in THIS ARTICLE, and well, for years now we haven’t found a better and more kosher way to compare the results.

The test – Comparison of Performance Max campaigns

For the comparison of the campaigns, we choose exactly one month (14th February to 14th March). During this time we monitored the development of multiple Google Ads metricsCPC, Clicks, Impressions, and CTR% with a highlighted focus on the CPC.

The metrics during this time looked like this:

observed metrics of
P.Max campaigns with Google CSS:
  • CPC – 0,30€
  • Clicks – 1515
  • Impressions – 116 573
  • CTR% – 1,30%
P.Max campaigns with Shopping in EU CSS:
  • CPC – 0,23€
  • Clicks – 2582
  • Impressions – 149 445
  • CTR% – 1,73%

The results – Summarization of metrics from both campaigns

As you can see, the campaign that used in Google CSS had a CPC higher by 0,08€ which in this case represents 23%. This is way more than any CSS Partner communicates and of course, can’t be attributed just to the CSS as such.

The Marketing Agency optimized the campaigns during the test and of course, this can reflect the changes on CPC. The reality is that when we compare the beginning of the test (the first week) we can see that the CPC from Shopping in EU P.Max campaign was 15% lower.

Something that you always need to take into consideration is that the percentage is never fixed, it varies from auction to auction and is always fluctuating.

We also tracked secondary metrics, from which we can see that numbers were increased by some percentage in the campaign that ran with Shopping in EU CSS. The campaign with our CSS had 70% more clicks, and 28% more impressions, and the overall CTR% was increased by 33%.

Statement from Marketing Agency:

It’s amazing that you’re not replacing your best-performing campaign, but adding another campaign that delivers a cheaper cost per conversion. We are not currently dependent on just one campaign, but we have two that are clearly the best performing in the account with their performance.

We are now seeing a 280% increase in revenue in the account compared to last year. We know that this number is not just due to the CSS campaign, but has a lot of credit to it.

As an agency, we are delighted with these results, and they are being communicated beautifully to the Berger-Huck client. So we are happy that the collaboration between Better and Shopping in EU has been realized.

Radovan Tondl – PPC Specialist at


We are fortunate to have partners such as Marketing Agency Better and clients like Berger-Huck. We would like to thank them for the opportunity to test the CSS on Performance Max campaigns, even if that meant increased spend for that month.

As you can see from the study, the CSS is still a viable solution if you want to advertise more through P.Max even if you use assets like photos, videos, and texts.

The CSS will take care of the CPC reduction on formats that it did before, which are Shopping and Dynamic Remarketing. The other formats will stay unaffected by the CSS and when comparing them separately can have higher CPC.

To finalize this article, we will tell you the same thing that we have been saying for years now. If you run P.Max or Shopping Ads on Google, not having a CSS partner other than Google just means that you are advertising with less power. Start advertising as you should, choose a strong CSS Partner, and reap the rewards.