Server-side tracking: combining compliance and performance

To analyse marketing performance or refine advertising campaigns, it is essential to understand customer behaviour on your website. For a long time, client-side tracking was the preferred method, due to its ease of implementation.

However, server-side tracking has emerged as a powerful alternative — particularly relevant as third-party cookies are phased out. It offers better governance, greater reliability, improved stability, and enhanced data enrichment.

🔎 This article aims to explain the differences between client-side and server-side tracking — and to highlight the key advantages of the server-side approach.

Tracking refers to the process of collecting and analysing online behaviour, both on the web and on mobile applications. It enables the creation of detailed reports on user activity and feeds advertising platforms with behavioural data.

There are two tracking methods:

Client-side tracking occurs on the user's browser or device using JavaScript scripts or tracking pixels. Data collection is managed by tags, which are triggered by a Tag Management System (TMS), transmitting information directly from the browser to the marketing destination.

Historically, client-side tracking has been chosen for web data collection due to its ease of implementation and ability to provide real-time results. However, this method has several limitations and drawbacks, particularly in terms of reliability, performance, security, and privacy.

The data collected via client-side tracking is becoming increasingly incomplete. Among the reasons for this are:

Client-side tracking is also affected by the potential loading of corrupted or malicious third-party scripts.

Conversely, server-side tracking is a data collection approach performed directly on the server. Data is collected and sent to a server, which then redirects it to a specific API or endpoint, such as Google Analytics, Facebook, or other data activation tools (CRM, marketing, analytics, etc.).

In this setup, the server acts as an intermediary between the user and the data destination, capable of performing additional processing on the data before transmission.

💡 Server-side tracking can also be implemented through its TMS, such as Google Tag Manager (GTM), which launched its GTM server-side version in 2020.

Server-side tracking offers numerous advantages over traditional client-side tracking. It improves web performance, enhances GDPR compliance, ensures more reliable advertising data, and enables the collection of a greater volume of information.

👇 For all the reasons described below, we highly recommend deploying server-side tracking to monitor activities on your website:

Server-side tracking is advantageous for counteracting data loss caused by ad blockers, browsers with anti-tracking features, or client-side connection latencies. These elements can alter tracking requests from the browser, underestimating traffic and actual conversions.

By migrating tracking to the server, which acts as a proxy between the user and the final destination, the risks of detection or modification by ad blockers or browsers are reduced.

Server-side tracking allows you to precisely determine which data is collected and, more importantly, when and how it is transmitted to external partners. This enables you to select essential information for your analyses and marketing initiatives while ensuring certain data remains confidential.

Additionally, you can filter personal or sensitive data to ensure privacy protection and GDPR compliance. By collecting user consent before data transfer and respecting their cookie preferences, server-side tracking offers complete data control.

Moreover, by choosing when data is sent to third-party platforms, this technology helps preserve first-party data over time, making it possible to recognise the same user over a longer period.

With server-side tracking, you can enhance the quality of data sent to external platforms by adding first-party attributes. For instance, you can associate user behaviour on your site with personal or demographic data for a more comprehensive view of your customers.

This practice allows for enriching hits sent to ad platforms, thus improving the match rate between your website users and the advertising platform users. A higher matching enables the creation of more complete and better-qualified audiences, thereby boosting the effectiveness of marketing campaigns.

Server-side tracking ensures constant stability in data processing, eliminating connection issues during peak periods like sales or Black Friday. This method reduces dependency on browser or client device performance, which can vary due to numerous factors.

Server-side processing relies on an infrastructure capable of handling heavier requests, making it easier to manage large volumes of data.

🌟 Server-side tracking benefits not only ads and analytics!

It also helps optimise your website’s performance, particularly by speeding up page loading times. By reducing the number of scripts and tags executed on the client-side, server-side tracking lightens the browser's load, promoting faster content display. This enhances the user experience and positively impacts SEO, as search engines favor fast and responsive sites.

Server-side tracking is recommended for two main reasons:

💡 If your organisation is just getting started with these topics, it’s best to first strengthen the fundamentals before considering server-side tracking. This remains an advanced technical solution that requires a solid understanding of both data and marketing challenges.

Server-side collection provides more detailed information, facilitating in-depth analyses. By limiting data loss compared to client-side tracking and maintaining first-party data over time, retention and attribution dashboards are much more accurate.

Server-side tracking is also a valuable asset for refining your advertising strategy by sending more complete and qualitative data to external platforms (Google Ads, Meta Ads, or other advertising networks). With server-side tracking, you can improve the match rate between various platforms.

This helps in better targeting and segmenting your audiences, generating more relevant lookalikes (based on more complete data), optimising your campaigns according to conversion goals, and retargeting more comprehensively your users.

Overall, implementing server-side tracking helps improve ROAS by providing more reliable and comprehensive data.

While server-side tracking appears to be an adequate solution for collecting and transferring online conversion data, it's possible to go further - particularly for ads and analytics in an omnichannel context.

In many cases, you don't just track interactions on your website. Event tracking is often spread across multiple point-to-point solutions used to fuel your activity:

All of these events are necessary to accurately reconstruct your customers' journeys. Taking them into account is essential for providing a 360° view of your customers. It helps assess the real impact of your advertising campaigns on actual sales (analytics) and enables you to optimise the algorithms of advertising platforms (ads).

The reality is that your customers may be influenced by your online ads but complete their purchase in-store — and vice versa. Ignoring these offline conversions could lead to a misjudgement of your campaigns’ effectiveness, ultimately affecting both your budget management and overall marketing strategy.

This is where the complementarity of a Customer Data Platform (CDP) truly comes into play.

To avoid losing events and double-sending all client touches, it's recommended to collect and the centralise all events (online and offline) in a cloud data warehouse.

⚠️ In any case, we advise against using your CRM as the Single Source of Truth, as data warehouses offer better functionalities for centralising and managing data collected by companies.

💡 If you need help setting up your data infrastructure, feel free to contact us! We'll be delighted to have a coffee break with you ☕️

These solutions facilitate direct communication between your server and advertising platforms. The advantage over server-side tracking configured on Google Tag Manager (or other tag managers) is that Conversions APIs are specifically designed to integrate offline conversion data by linking it to online interactions.

Here again, it is possible to add first-party data to these conversions to enrich them as much as possible, thus improving the matching rate on the ads platforms. This technique allows you to link each offline conversion to the corresponding advertising campaign, offering more detailed and reliable ROI analyses.

Most advertising platforms (Meta, Google, Tiktok, Snapchat) provide Conversions APIs.

💡 If you want a solution that allows you to do both simultaneously, use tools from DinMo! Our solution enables you to send both online and offline conversions directly from your cloud data warehouse in just a few clicks. You can also modify your conversion values afterward.

Server-side tracking emerges as a robust solution for collecting and managing web and mobile data, operating from a server rather than from the user’s browser or device. This method offers notable advantages over client-side tracking, providing greater reliability, better performance, enhanced security, and a more privacy-respectful approach.

Server-side tracking is recommended for adopting a data-driven approach and improving advertising effectiveness. It enables the transmission of richer and more reliable data to third-party platforms. Additionally, using conversion APIs makes it easier to integrate offline data, providing a more complete view of the customer journey and a more accurate calculation of return on investment.

In short, these technical solutions are essential for increased marketing efficiency, and we highly recommend their implementation.

If you want to learn more about server-side tracking solutions or Conversions APIs and their implementation, feel free to contact us. We would be happy to share our best practices on data marketing topics!