The linking of campaigns and conversions is carried out using Google Click ID. We do not consider the Google Click ID as a personal data. The Click ID is used exclusively to measure success and enables the assignment of conversions to corresponding Google Ads. Remarketing in the sense of allocation to individual users and their targeted advertising is therefore excluded. The use of imported conversion data for target group segments is not possible. The data processor therefore has no way of identifying the user behind the Click ID, and it is therefore not possible for the website operator to identify the data subject on the basis of the Google Click ID. Thus, the conversion data uploaded to Google Ads does not refer to a natural person and the Click ID is not an online identifier in the sense of https://gdpr-info.eu/recitals/no-30/.
A combination of conversion data with user data for Google’s own purposes alone, which remain hidden from the advertising company, cannot be fundamentally ruled out. This is because every click that comes via an advertisement is evaluated by Google with an individual Google Click ID (GCLID). Google could theoretically merge the conversion with other tracking data on the respective user if Google carries out a matching of generated click IDs and user IDs. However, the fact that “target group segments” and “remarketing” are excluded by means of GCLID and requires the transfer of other identifiers or the implementation of Google tags speaks against this, see for example: https://support.google.com/google-ads/answer/9199250?hl=en-GB.
Although Google does not explicitly exclude the merging, Google has, for example, published documents in which the upload via Click-ID is explicitly advertised as fulfilling strict data protection requirements (see https://www.thinkwithgoogle.com/_qs/documents/4066/comdirect_Offline_Conversion_Tracking_07.pdf). Therefore, we consider it responsible to see this as a credible confirmation that a purely Google-internal identification based on the Google Click-ID does not take place.