The Dual Approach to Analytics Tracking: Client-Side & Server-Side

In the analytics field, the choice between client-side and server-side tracking is pivotal for data-driven businesses.

Adnan Khan, Co-Founder of Stitch and Chair of the Marketing Association’s Digital Special Interest Group, dissects these tracking methods, highlights their pros and cons, and advocates for a hybrid model to enhance customer insights.

Whether your focus is on accuracy, completeness, or timeliness, his insights offer practical guidance for tailoring your tracking strategy to meet your specific business requirements.

While numerous articles sing the praises of product & behavioral analytics tools like Google Analytics 4 and Mixpanel, extracting maximum value from these platforms depends largely on your user action-tracking approach and future expansion plans.

The inevitable conundrum that every data-driven enterprise faces is choosing between client-side and server-side user action tracking. In essence, the choice is not absolute. Here, we delve into the nuances of both tracking methodologies, weighing their strengths and drawbacks, and emphasizing the importance of employing a hybrid model for an encompassing view of the customer experience.

Understanding the Two Tracking Mechanisms

• Client: Refers to the medium the user engages with your product through, be it a mobile application or a web browser. 
• Server: Represents the backend system that updates content on the user's mobile or browser based on their interaction with your product.
• Client-Side Tracking: Data is relayed directly from the user's device/browser to your analytics tool.

• Server-Side Tracking: The backend system transfers data to your analytics tool.

The Ideal Analytics Landscape

In an envisioned utopia of analytics tracking:

• Accuracy prevails with a consistent and reliable dataset accessible by all.
• Completeness ensures all relevant data, from UTM parameters to valuable metadata, is at hand.
• Timeliness guarantees near-instant data access.

However, the desire for perfection is marred by associated costs. Client-side tracking costs grow with user volume, and the backend grapples with storage costs and ETL processes. The price of storing even unutilized data still remains.

Client-Side Tracking: Benefits & Challenges

The benefits:

• Hassle-free setup.
• Quick turnaround with reduced developer efforts.
• Regular vendor updates including privacy-centric changes.
• Efficient anonymous user data tracking.

The challenges:

• Susceptibility to ad-blockers causing event loss.
• Inconsistent metrics across platforms.
• Slower rectification of mobile integration errors.
• Eventual divergence due to dated mobile versions.
• Batching, connectivity, and downtime can skew data accuracy.

Server-Side Tracking: Strengths & Limitations

Strengths:

• Reliable data, reflecting the same values for everyone.
• Data consistency, unaffected by old clients or OS.
• Easier error rectification and backfilling.
• First-party tracking ensures privacy.

Limitations:

• Time-consuming and complex setup.
• Prolonged development time for custom tracking models.
• In-house support is needed for changing privacy norms.

Practical Steps for Effective Analytics

Relying solely on a perfect system is futile. It's about striking the right balance between client-side and server-side tracking.

A Robust Hybrid Model Involves:

Client-side Approach:

• Track unique clickstream data unattainable server-side.
• Use proxies to mitigate ad-blocker-induced event losses.
• Standardise a tracking plan for each OS.

Server-side Strategy:

• Ensure "key metrics" are server-tracked.
• Implement retries and logs for uninterrupted analytics during client downtime.
• Enrich with historical data capabilities and allow backfilling when needed.

Source: Adnan Khan,  Stitch, 15 October 2023.