The problem with client-side tagging
With traditional tagging, whether you are using Google Tag Manager or putting tracking scripts directly into your site, the browser has to download all those third party scripts before sending the data directly to those external services.
This has a few consequences:
- External tracking scripts can add up to many megabytes, thus slowing down your site for your users.
- External tracking scripts are far more likely to be blocked by browsers and blockers.
- You are not in control about the data that those tracking scripts send.
The benefits of server-side tagging
With server side tagging you create and are in control of your own tracking server, running on your own subdomain. With this setup, the browser sends requests and data directly to your server. Once the data is received by your server it can then be routed to other tracking scripts. This approach has many benefits:
- You can significantly improve page load times because those external tracking scripts are no longer downloaded and executed by the browser.
- Reduced impact of ad blockers since the tracking code is hosted on your server.
- Much better privacy controls. Since the data arrives at your server, you decide what data to send to third party scripts. Filter out sensitive data such as IP addresses and cookies.
Create realtime data apps
Because you have full control over your own tracking server, you can create advanced apps with relative ease.
- Send realtime cart events to a database to see what items your users are adding to cart.
- Track error messages in realtime so you can detect problems right away.
- Send data to a data warehouse like BigQuery for longterm storage and advanced analysis.
- Full access to raw traffic data and server logs.
