Google Analytics, consent & CMP

Anaïs Pernin -

Today, only a  few analysis solutions received an official exemption from the french DPA  « the CNIL », but the most common one is apparently not on this list because up to now, Google seems not to have filed any file for its Analytics suite.

The Google Analytics tag, which allows the deposit and reading of cookies by default, should therefore only be triggered after having obtained the consent of the Internet user for audience measurement.

However, there is an alternative for recent Google Analytics tags: the Consent Mode. This setting will allow Sirdata CMP to automatically block the functionality of depositing and reading cookies from Google Analytics. Thus, with this option, it is no longer necessary to condition the tags of the latter to avoid the use of cookies.

In fact, Sirdata CMP will send a signal to Google that allows it to automatically operate in under the standard mode or under the cookieless mode in case of non-consent. This will enable the continuity of the Analytics service and this, always respectfully of the user's choice.

However, without cookies, simple events such as the deduplication of visitors for the calculation of the number of unique visitors, or the tracking of out-of-session sales are severely disrupted, if not made impossible. As a result, significant discrepancies can be observed and up to 30% of visitors can disappear. This is normal and does not mean the traffic did dropped.

The modeled online conversions will gradually allow Google to fill these measurement gaps. The latter uses machine learning to quantify the correlation between users who gave their consent and the others to extrapolate the paths of users who do not give their consent.

Since April 2021, the signals Sirdata CMP is being sending to Google enable the activation of this modeling for "conversion measurement" (attribution). Thanks to it, the campaign statistics benefit from these corrective measures.

Up to now, the signals are unfortunately sent for "audience measurement", but the learning phase is not over and Google still didn’t confirmed any date for the statistics displayed in the console to benefit from this modeling.

To remedy this temporary lack of visibility of statistics, publishers can turn to CNIL exempt analytics solutions but these ones are often not free of charge.

Other publishers are testing an exclusive option in beta : Sirdata Analytics Helper, which aims to close this gap in Google Console statistics even in the absence of consent but still in compliance with the regulatory framework.

  • In your Sirdata CMP interface : Check the "Google Ads/Analytics/Tag Manager compatibility" extension in "Edit display" / "Advanced settings / Extensions".
  • Make sure you use a recent gtag() or tagmanager tag (since the option is not compatible with old ga() tags)
  • Make sure you don't / no longer condition your Analytics tag.
  • Make sure the CMP is loaded before all your other tags (including the Analytics tag).


If you are interested in the Sirdata Analytics Helper feature, please contact the Sirdata team to get more details about the prices and activation terms.