The key benefits of Server-Side Tagging, and why it is highly beneficial to Marketers, Advertisers, e-Commerce entities, or anyone that needs to track conversions in general.
OVERVIEW: GTM SERVER-SIDE TAGGING & GOOGLE ANALYTICS 4 (GA4)
The Benefits and Use-Cases of Server-Side Tagging
Before explaining the mechanics of Server-Side Tagging (SST) and how it contrasts to Client-Side Tagging (CST), it is beneficial to first highlight some of the key benefits of Server-Side Tagging, and why it is highly beneficial to Marketers, Advertisers, e-Commerce entities, or anyone that needs to track conversions in general.
Server-Side Tagging gives marketers more centralized control of user's data and allows them to transform and manipulate user data at will before sending it onto 3rd Party Platforms. For example, one can make sure that PII from users is removed from data before being passed onto 3rd Party Platforms. You could also amend, remove and transform specific data before sending it to different platforms.
SST allows you to save resources, including improving the user's interaction with your website. A typical case is improving page speed - since requests are sent to and from the client's browser directly to your tracking server, rather than a remote 3rd party. Improving page speed also enhances user experience thus reducing user dropoffs. Another use-case would be in sending a single request to your tracking server rather than multiple disjoint requests.
SST allows marketers to circumvent different protection issues arising from specific 3rd party domains (e.g. Adblockers). A specific and important case is to circumvent Apple's ITP (Intelligent Tracking Protection) - which purposefully blocks 3rd party cookies.
With the ongoing deprecation of 3rd Party Cookies on Mozilla, Safari, and (in the near future) Chrome, SST allows you to perform e-commerce and conversion tracking of users without the need for 3rd Party Cookies. In Safari, for example, your cookies have an expiration of between 1 to 7 days. Client-side tagging relies on cookies to store information on (for example, returning users), which they can then link to their internal data about the user when the user returns to the website. Cookies are needed in the Client-side scenario primarily because Client-Side Tagging sends data to platforms such as Google Analytics, rather than a tracking server that the website owner controls.
SST is inherently more secure in terms of Data Privacy, as a user interacting with your website sends data only to that website's tracking server - rather than to 3rd Part Tracking Platforms.
Complex Sales funnels - where the user does not convert on their first visit, or scenarios where the user converts Offline after (for instance) a sales call, rather than an online "Check out" button, are good candidates, for SST since the user's data is sent to your tracking server, rather than a 3rd Party platform such as Analytics.
In order to better understand Server-Side Tagging (SST), one needs to first understand the mechanics of how Client-Side Tagging (CST) works.
In CST, there is therefore a direct connection between the client browser and the specific tracking tools used to track user events and sessions, e.g. GTM, GA, FB Pixel, etc.
Traditional website configuration without server-side Tag Manager:
In Server-Side Tagging, we implement a tracking server, which is the endpoint that can then send data directly to 3rd Party Tracking tools. The information from the user's events is sent either (1) directly to the 3rd Party platform (as in client-side) or, (2) directly to the tracking server (hence bypassing the 3rd Party Platforms, e.g. Facebook Events Manager, GTM, GA, AdWords, etc.)
From the newly-implemented tracking server, data is sent first to the tracking server and subsequently distributed to any number of 3rd Party Tracking platforms.
Within the SST paradigm, you can choose to create your Google Cloud Platform (GCP) cloud server instance to act as your tracking server. When a tag fires the data is sent first to your tracking server, which then can send that data to other tracking tools, such as Google Analytics, Facebook Events Manager, etc. Website configuration with server-side Tag Manager: