Google Consent Mode: how to collect and process your user data in the era of GDPR?

Apple’s recent decision to subject the tracking of application users on iOS14.3 to their consent has shaken the world of GAFA and, more broadly, the web marketing industry. Inevitably, this App Tracking Transparency imposed by the Apple brand on application publishers deprives them of part of the data that they monetize at exorbitant prices. For Facebook, this could, for example, lead to the exit from the radars of a quarter of users…

From Apple’s point of view, this is in fact a major issue of the user experience, of which we recently reminded you of the central position in the web economy. And it is difficult not to agree with them, as the protection of personal data has become essential in the relationship of trust between digital players and their customers.

However, Google, whose interests on the issue of “cookie consent” are more ambiguous than those of Apple, has also long been in favor of the protection of personal data. Recently, they launched the Google Consent Mode in beta version. And this interface is destined to become the reference interface in terms of GDPR constraints for most companies that have implemented a strategy for collecting and processing user data for marketing purposes.

However, this is an issue that is not always mastered, or even totally ignored by some advertisers.

So that, in a nutshell, is what you need to know to combine GDPR-compliance and economic competitiveness in the approach to personal data.


  • What is Google Consent Mode?
  • 2021: the new CNIL guidelines on GDPR
  • “Cookie consent” and GDPR: should we resign ourselves to less efficient Google Analytics?
  • Do you have to go through a Consent Management Platform (CMP)?
  • UX design: your best asset against the loss of your user data
    • Frequently Asked Questions
    • How does Google Consent Mode work and what is its purpose for collecting user data?
    • What are the best practices for implementing Google Consent Mode on your website?
    • How can Google Consent Mode help improve trust with users?

What is Google Consent Mode?

Tracking users’ online behavior is of strategic interest to companies, especially those that leverage online advertising to convert customers. With this in mind, the personal data collected from the various targeted audiences can significantly improve ROAS.

But, in recent years, the legislator has imposed a certain number of limits on these practices (in Europe, this now involves the GDPR) and advertising agencies have adapted their environment to them. On the side of the Alphabet group, this has recently resulted in the development of Google Consent Mode, which is an API allowing the operation of a website to be adapted to variations in user consent.

Basically, Google Consent Mode allows site owners to automatically determine how scripts and tags related to Google Analytics and Google Ads should be triggered on their sites.

Proper use of this Google “SEO for Vacation Rentals” is essential to combine compliance with the “consent cookie” and effective processing of user data (especially with extensive use of Google Tag Manager).

In practice, it is the new CNIL guidelines that make this API essential.

2021: the new CNIL guidelines on GDPR

The first applications of the GDPR have caused a lot of ink to flow, before and after its entry into force on May 25, 2018.

Most web players agreed on the need to regulate the processing of personal data, but the legal obligations put in place for this purpose proved unpopular. In particular, they have been singled out for their inadequacy with the reality of online business.

This did not discourage the CNIL from applying, on March 31, 2021, new directives confirming the legal obligations on user consent to targeted advertising.

From now on, there is no doubt: Internet users must be clearly informed and have just as clearly given their consent for everything concerning the filing of certain tracers and the processing of the resulting data.


  • The mere continuation of navigation on a site can no longer be considered as consent.
  • Users must consent to the deposit of tracers by a clear positive act (egg clicking on “I accept” in a cookie banner).
  • They must be able to withdraw their consent at any time.
  • Rejecting tracers should be as simple as accepting them.
  • The consequences of accepting and refusing tracers must be clearly explained.
  • The organizations using the trackers must be able to provide proof of obtaining consent.
  • Site owners can no longer deny access to content to their visitors subject to the acceptance of cookies.

However, as you surely know, no one is supposed to ignore the law, and, for once, compliance with this law is likely to degrade Analytics performance …

“Cookie consent” and GDPR: should we resign ourselves to less efficient Google Analytics?

It is expected that the application of these 2021 CNIL directives could cause the loss of up to 50% of user data on certain web environments. It is therefore natural to expect a decline in the quality of online advertising targeting at the same time.

However, this is not a fatality.

Without wanting to be overly optimistic by denying any impact of the GDPR on advertising targeting, a professional and expert approach to the issue should make it possible to limit most of the damage on the side of the use of your Google Analytics and Google Ads tags.

On the one hand, the drop in the volume of data collected does not necessarily imply a proportional drop in the quality of advertising targeting. It is also the role of an Marketing for Schools to develop targeting strategies that adapt to the state of the data and maintain a high level of performance.

On the other hand, there are solutions to limit this loss of data, in particular the controlled use of a consent management platform.

Do you have to go through a Consent Management Platform (CMP)?

According to Google, yes. That’s what they recommend.

These platforms connect to the Google Consent Mode API and in fact make it possible to automate and sustain its use on a website. They also make it possible to retrieve evidence of the collection of consent. There are several on the market, the best known of which are Aseptic, Dido mi and One Trust.

At Ad Premier, our position on the subject follows Google’s recommendation. There are of course alternative solutions to “consent mode” via CMP (such as the use of trackers not subject to consent, or the readjustment of objectives according to Troas or cap), but they are generally more time-consuming and less efficient.

On the other hand, the effective use of Google Consent Mode via a CMP makes it possible to exploit the personal data of users to the maximum of what the law authorizes while reducing the technical burden that this represents.

All that remains is to convince your users to let you trace them and, for that, you will have to put the package on the UX design.

UX design: your best asset against the loss of your user data

Once your environment for collecting and processing user data has been brought into compliance with the GDPR, there is no reason to resign yourself to losing 50% of this data. On the contrary, with a user experience-centric approach, you can earn the trust of your site visitors.

In this case, the first rule to respect and to play the card of transparency. You are a company and therefore have commercial objectives. Visitors to your site know this. There is no reason to hide it. Your goal should rather be to promote a common interest between them and you in the collection of personal data.

Consumers, especially the youngest, are often less reluctant to transmit their data than advertisers think… Provided they obtain a better user experience in return.

Your “cookie consent” message must therefore be worked in this direction. But you must also be careful about how you will display it on your site when your visitors arrive.

Recent tests in this area show, for example, that banners in pop-up format obtain a better consent rate. It would also seem that banners with pre-checked parameters lower this consent rate (not to mention their uncertain legality from the point of view of the new CNIL directives).

But these observations have nothing to do with general truths. In practice, every audience is different, and we can’t recommend testing different messages and formats to see what works best with your own visitors.

Be that as it may, this problem of consent to tracking can no longer and must no longer be avoided. Any company that has ambitious online acquisition goals must rely on a serious GDPR approach today. The Google Consent Mode offers an effective lever to deploy this approach and secure the use of your user data in your online advertising strategies.

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