When measuring (non-)consents on e-shops and websites we use a completely unique method to detect the exact number of visitors who gave full, partial or no consent. We call it Consent Rate and Decline Rate.
Consent Rate and Decline Rate
Consent Rate counts the total number of full consents + partial consents against the total number of cookie banner views.
Decline Rate counts the total number of visitors who rejected all cookies against the total number of cookie banner views.
The last indicator is the so-called Undecided Rate, which represents undecided visitors and to some extent also reflects the bounce rate (a visitor came and left right away).
How the Measurement Itself Works
Consent Rate is measured differently from classic event tracking in GA4. The basis is a correctly set up Google Analytics 4 Measurement Protocol (MPGA4), which, within a single GTM container, sends the consent measurement to a separate GA4 property.
The Following Events Are Measured Within MPGA4:
- page_view
- entrance
- consents_banner – display of the banner (cookie banner)
- consents_accepted_all – "I accept all consents"
- consents_rejected_all – "I reject all consents"
- consents_selection – "I'll choose only some"
- consents_link_cookies – link to information about cookies
- consents_settings – adjusting the consents that the visitor wants to confirm
- consents_changed – an event that measures a later change of consent
- consents_interaction – the interaction itself with the switches of individual consents
For correct measurement you need to define the individual variables cookies, consents_id and the ID of the new GA4 property.
The MPGA4 Event Itself Then Looks Like This:
//region1.analytics.google.com/g/collect?v=2&tid={{GA4.ID.cookieless}}&cid={{JS.getSessionId}} &en=page_view&dl={{Page URL}}&dr={{Referrer}}&dt={{Page Path}}&gcs=G111&ep.consents=fun~{{LookUp.cookie.neccessary}}~~ana~{{LookUp.cookie.analytics}}~~ads~{{LookUp.cookie.marketing}}~~per~{{LookUp.cookie.viewed}}&ep.consents_id={{CO.CONSENTID}}&ep.user_agent={{JS.userAgent}}&_dbg=1
Explanation of the parameters:
CO.CONSENTID is a variable that contains the consent ID generated by the given consent management solution; it is used to look up the time consent was given and for other disputes with customers
gcs=G111 is set mainly for debugging reasons (G100 hits are not visible in debug view); by default it is then possible to send G100
the whole hit can also be run through an anonymisation proxy, which removes all potential information about the IP, user agent and so on.
The processes above must always be consulted with the client and their legal department, asking what data about customers they allow to be collected this way. For example, for the German market we would go the following way: use an anonymisation proxy, send the data as G100 even at the price of worse reporting, do not send the user agent but only the browser type and version for debugging purposes.
The Overall Consent Rate Report
We deliver the resulting report in Google Looker Studio (originally Google Data Studio), where you can see over time how visitors' willingness to give full consent changes, or how the rejection of all consents changes.
The figure in the report shows the nominal numbers of visitors by their type of consent over a given period. Next to the nominal values you can also see the percentage, which is calculated as the total number of visitors by consent / number of cookie banner views.
Further filters and settings enter into the numbers so that they correspond to the new property in GA4.
Consents vs Purchase is a table that shows how many purchases took place in the mode of full, partial or no consent. You can thus easily find out how many purchases will be missing in GA4 (rejected_all) and work out the real purchase data (purchase).
The same principle can be applied to other areas and events on the e-shop / website. For example to form submissions, newsletters, e-book downloads, registrations and so on…
Have us measure consents/non-consents on your e-shop or website using Consent Rate. You will find out the exact number of visitors together with a detailed and clear report, charts and tables.