Consent Mode and More

2022-09-02 | Article | Insights


Google Consent Mode is a tool that simplifies the control of Google tags, taking into account the consent or rejection of cookies by the website visitor. At the same time, Consent Mode provides valuable data that can be used to model conversions, for example, which would otherwise be impossible to measure. The modelled data can be used for more precise campaign management, for example with Google Ads, and thus Consent Mode supports advertisers in campaign optimization.

It is becoming increasingly difficult for marketers to measure the success of digital campaigns on business objectives. Tracking restrictions, changes in the way browsers handle third-party cookies, as well as the General Data Protection Regulation (GDPR) reduce the available data that is needed for campaign control and optimization. For example, conversions can only be measured if a website visitor gives consent to cookies. If cookies are refused, important actions that a user takes after arriving on the website via an advertisement cannot be tracked.

The Google Consent Mode supports by controlling the display of Google Tags depending on the consent of the visitor. If a website visitor does not consent, lost conversion data is "recovered" by means of data modelling.

What exactly is Google Consent Mode?

Google Consent Mode is the answer to increasingly strict regulations and data gaps. Consent Mode is designed to close the data gap and enable marketers to get a holistic view of their website's user behaviour. Missing data is to be "supplemented" by machine learning and data modelling, so that a holistic view of the data is reflected.

In order to track which interactions a user performs on the website, most corporate websites use conversion tracking. If a website visitor performs certain actions, for example, informs himself about a product on a product detail page or adds a product to the shopping cart, these interactions can be measured and used for marketing purposes. This information is collected in a cookie and can be used by the advertiser. However, according to the GDPR, this is only allowed if the website visitor has explicitly given consent to the measurement of the data. The GDPR is the basis under data protection law for the collection, processing and storage of personal data in the EU. Cookies also count as personal data, as they can be clearly assigned to a user, for example via the client ID.

For example, Google Analytics requires cookies in order to be able to assign the user interactions that took place during a session to this session. Google Ads and the Google Display Network also use cookies to collect relevant information about the user, which in turn can be used to optimise advertising campaigns. It is therefore extremely important for advertisers to obtain the consent of website visitors via cookie banners. This ensures that this data can still be accessed for the optimization of digital marketing measures...

Google Consent Mode is an API provided by Google to control the behaviour of the Google tools used on the website. Two new tag settings, analytics_storage and ad_storage, were introduced for this purpose.

Based on the consent of the website visitor, Google tags, which are used for the integration and use of Google Analytics, Google Ads, Floodlight and Conversion Linker, for example, are activated or deactivated. If a visitor consents to the collection, processing and storage of their data on the website, the tags are fired as usual and cookies can be set. If the website visitor declines, however, the respective tags are still fired, but no cookie is set for advertising purposes and statistical data and conversion data are not measured. Thanks to modelling, the data is not yet completely "lost".

Google Consent Mode is not a Consent Management Platform (CMP). The Consent Mode cannot display cookie banners, nor does it take over the documentation of the customers' consent. Other technologies such as a meta pixel are not controlled by Consent Mode. Therefore, a Consent Management Tool is required in addition to the Google Consent Mode.

How can Google Consent Mode be used?

The implementation of the Google Consent Mode requires that the Google tags used have been installed via the Global Site Tag (gtag.js) or the Google Tag Manager (GTM). The Consent Mode uses the dataLayer to transmit the two parameters "analytics_storage" and "ad_storage" mentioned above. These two parameters can be transmitted with either "granted" or "denied" depending on the cookie consent and thus control the cookie behaviour for analytics and advertising purposes.

It is recommended that the two parameters "analytics_storage" and "ad_storage" be configured to contain region-specific "default" values when loading each page. This helps to avoid losing measurement of users from regions where cookie consent is not required if the "default" value for the two parameters is set to "denied". The default consent status must be available when loading each page before the tags are loaded.

The cookie banner passes the information about the consent or refusal of the website visitor directly to the Google Consent Mode. This executes an "Update Consent State" event and sets the two parameters to either "granted" or "denied".

Google Analytics can be controlled with Google Consent Mode. For this purpose, the parameter "analytics_storage" is available, which controls the tag settings of the Analytics cookies. If a website visitor refuses the use of advertising cookies but gives consent to Analytics cookies, advertisers can still measure behaviour and conversions in Analytics. However, Google Analytics is also able to read the "ad_storage" parameter and will not be able to write or read advertising cookies in the absence of consent. This affects functions such as remarketing.

"ad_storage" controls the behaviour of all cookies used for advertising purposes and conversion measurement. A user visits the website and consents to the use of advertising cookies. Google Consent Mode allows the fired Google tags to determine if the website gives permission to use cookies for advertising purposes for that website visitor. Since the user has consented, the conversion measurement is performed as usual. However, if the user refuses to use advertising cookies, the fired Google tags will be adjusted so that they do not use advertising cookies. Conversions are then recorded on an aggregated level and by means of modelling.

More conversions thanks to modelling

If the user gives consent to the use of analytics and advertising cookies when visiting the website, tracking works as usual. The corresponding tags are fired, cookies are set in the browser and the data is transmitted as usual. However, if the user refuses the use of these cookies, Google Consent Mode prevents Google tags from setting the corresponding cookies and thus collecting data. To ensure that the data is not completely "lost", Consent Mode uses "anonymous pings" to continue collecting important anonymised information.

With these "pings", limited functional information and aggregated data are forwarded to the platform. Only data on interactions that have taken place on the website are transmitted. Strictly no advertising cookies are set or read. This removes the ability to identify a website visitor and it is not possible to link specific ad interactions to website interactions such as a conversion. Only the fact that an event or conversion has taken place is recorded.

If the user does not give consent to analytics cookies and the "analytics_storage" parameter is therefore set to "denied", pings, page views and events are recorded in the form of completely anonymised pings. These are aggregated and cannot be linked to the user, as each ping receives its own user ID. The data then runs into a modelling pool to make sessions, users or conversions reusable through machine learning.

The advertiser thus has more valuable information at his disposal when integrating Google Consent Mode than without Consent Mode. The pings sent are aggregated in a pool. Google uses this information to model the "lost" conversions as precisely as possible and to play the information back to the ad systems or Google Analytics. According to Google, more than 70% of the ad click-to-conversion journeys can be reconstructed in this way, which would otherwise have been lost due to missing cookie consent.

More data equals better campaign optimizations

With the introduction of cookie banners on websites, it is easier for users to refuse cookies and thus make their website behaviour unavailable to the website operator. This leads to more and more incomplete data being collected and important decisions such as budget optimization having to be made on the basis of this incomplete data. This is an increasingly difficult task for an advertiser to manage. With advertising spend under constant pressure to optimise, attributing conversion to campaign is a high priority for advertisers. With the insights gained, campaigns and bidding strategies can be optimised. Google Consent Mode provides advertisers with more insights on conversion data through data modelling, while ensuring that only data that has received the website visitor's consent is measured.

Even without website visitor consent for analytics and advertising cookies, Google Consent Mode allows, for example, conversion measurements to be extracted from campaigns and website traffic. The data does not contain detailed information about the visitor. By using Google Consent Mode, advertisers still receive valuable information that can be used to optimise campaigns and budgets.

More accurate conversion rates

Google Consent Mode allows for a closer look at the conversion rate. If an advertiser has not integrated a Consent Mode, no information is available about the consent status of the website visitors. It remains an unknown number how many website visitors have accepted or rejected cookies. Here is an illustrative example: Out of 100 website visitors, 10 visitors convert, which corresponds to a conversion rate of 10%. With integrated consent mode, the advertiser can differentiate how many visitors have accepted the cookies and how many have rejected them. Another example to illustrate how the Consent Mode can make the conversion rate more precise: Assume that out of 100 website visitors, 70 people agree to the cookies and 30 people reject the cookies. If ten visitors who have allowed cookies now convert, this results in a conversion rate of 14%. Consent Mode uses this 14% conversion rate as a modelling aid to determine a more precise conversion rate, which is made up of the actual conversion rate and the modelled conversion rate.


One of the most important points to understand is that Google Consent Mode cannot replace a Consent Management Platform. It helps with the targeting of Google tags and can still collect valuable data if cookies are rejected. Machine modelling can thus determine more precise conversion rates, which in turn help to optimise campaigns and bidding strategies. Google Consent Mode illustrates that anonymised data in combination with machine learning can also contribute important pieces of the puzzle to the holistic view of user behaviour with advertisements or on the website. All in all, Google Consent Mode is an increasingly important component for the future of tracking, with which one should already familiarise oneself.

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