Can be used together to analyse web traffic and to gain an understanding of the performance of ads.
Google Analytics and Google Tag Manager are both tools that allow website owners to understand their visitors and assess the success of their content and advertisements. These tools are easily accessible, free, and very useful for website owners. However, the cost is that they also share all the analytics data with Google. This data ranges from information about time spent on specific portions of the website to the amount of visits, interaction with content, and a whole lot more.
Because they own the tools with which they analyse the effectiveness of their ads, Google continuously improves the quality and relevance of those ads. This power only further establishes them as the go-to advertising giant they already are. Website owners which use Google Analytics and Google Tag Manager are given access to parts of this data, but Google holds the real advantage here. By assembling all the data from websites using these services, they can combine it all to train way better and more accurate models and algorithms.
A recent study showed that many academic libraries, often seen as institutions that should be the advocates for the privacy of their users, actually use Google Analytics or Tag Manager without proper IP anonymization . This goes to show how widespread this problem really is, and that without government interference this is not liable to change.