The Future of Data-Driven Marketing: Server-Side Tracking and First-Party Data

Data-driven marketing is defined as a marketing approach that relies on customer data to guide decisions, targeting, and creative strategies. As third-party cookies disappear due to privacy regulations like GDPR and changes such as Apple’s iOS 14 update, the industry is shifting to server-side tagging, Conversions API (CAPI), and first-party data collection through loyalty programs and authenticated experiences.f

Firstly, privacy laws and the crackdown on big tech have gradually reduced the value of cookie-based tracking. Legislation like GDPR and changes such as Apple’s iOS 14 update have made it harder for businesses and other tech companies to track user behaviour. Many of the larger tech players are now working on or closely observing how they need to change their operations to adapt to the depreciation of third-party cookies and the new privacy-driven landscape.

The challenge at hand is that cookies have long served as a key identifier for individuals online—or a great proxy, so to speak. They’ve allowed unified targeting across channels. With this capability disappearing, the big companies are pivoting to build direct relationships with users and encouraging them to stay logged in across platforms.

Without cookies, tech giants can no longer track users across the web in the same way. To maintain visibility, they’ve incentivised as many brands as possible to adopt methods like server-side tagging or CAPI. This approach is critical to retaining insights on media targeting and performance. Without it, media and marketing investments could lose their edge.

How do server-side tagging and CAPI work?

Let’s take a step back to explain. Companies like Meta and Google placed their cookies on countless websites, driven by the popularity of tools like Google Analytics, Google Ads, and Google Tag Manager, or Meta’s tracking pixel. This enabled these companies to act like omnipresent observers, creating detailed profiles for each cookie and selling insights through targeted advertising products.

Now that cookies are disappearing, the challenge has been to find new ways to observe user behaviour across the internet—preferably as close to personalised, one-to-one tracking as possible. The solution? Leverage businesses themselves to provide data. Enter server-side tagging and CAPI. Instead of silently observing user behaviour via cookies, tech companies now have businesses report back user actions, like purchases or specific website interactions.

How does this work? Businesses are encouraged to identify visitors to their digital properties. In exchange, they get clearer visibility of their media performance, while companies like Meta and Google retain the ability to build user profiles. This has led brands to incentivise users to identify themselves—through personalisation, loyalty programmes, and discounts.

Why are businesses adopting loyalty programmes and first-party data?

This shift has driven the growth of brand apps and loyalty programmes. These tools provide a way to collect data in exchange for a better customer experience. The data businesses gather is then fed back to platforms like Meta and Google through anonymised identifiers. While the process adheres to GDPR, it replicates the purpose cookies once served: tracking user behaviour, albeit with users now “wearing a mask.”

In some ways, we’ve gone full circle. Yet, this time, users gain something back. Beyond GDPR’s rights to know and delete their data, users can now trade their identity for tangible benefits like discounts and personalisation. This trade-off is slowly reshaping the marketing ecosystem, balancing power between businesses and individuals.

What is the identity layer being added to the internet?

Broadly, this transition is adding an identity layer to the internet. Governments are also playing a role, introducing legislation and pushing for greater oversight. For instance, there’s a growing trend to weaken end-to-end encryption in messaging services under the guise of safety. While exchanging privacy for security is a questionable trade-off, it illustrates the broader push towards identification in the digital space.

What does this mean for personalized marketing experiences?

Key Takeaway

Businesses and governments alike are incentivising users to share their identity. The number of anonymous web sessions is shrinking, replaced by increasingly personalised interactions.

As we touched on earlier, loyalty programmes and digital experiences are evolving. Imagine a world where your entire online journey is tailored to you. On a golf equipment website, for example, your experience might include products based on your past purchases, geography, and skill level. It could even suggest your next golf game or offer a VR simulation to help you improve. The possibilities are as broad as your imagination.

Restaurants could present customised menus reflecting your taste preferences—or ones designed to challenge them. Larger brand collaborations could result in entire ecosystems of services adapting to your preferences, creating a truly one-to-one experience at scale.

What is the future of personalized marketing?

With the rapid development of AI, personalized marketing is evolving towards hyper-personalization.

As brands increasingly collaborate and share data, we’re on the brink of creating hyper-personalised ecosystems. Imagine a cluster of related products and services all centred on your unique preferences. One-to-one at scale becomes not just a possibility, but a standard.

How should marketers prepare for the future?

The future of data-driven marketing is closer than most people think. We’re witnessing the convergence of identity, AI, and personalisation in ways that will fundamentally reshape how businesses interact with customers. The question isn’t whether this will happen—it’s whether we’re ready for it.

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Key Takeaways

• Third-party cookies are disappearing due to privacy regulations like GDPR and browser changes
• – Server-side tagging processes tracking tags on your server instead of the user’s browser
• – CAPI (Conversions API) sends conversion data directly from servers to ad platforms
• – Businesses collect first-party data through loyalty programmes in exchange for personalization
• – Users exchange identity for benefits like discounts and tailored experiences
• – AI will enable hyper-personalized marketing at scale across websites, apps, and physical stores
• – The internet is adding an identity layer with fewer anonymous sessions

Updated: February 2026

Fifteen months after publishing this piece, the predictions have largely materialized—though the pace of change has exceeded even optimistic forecasts. Google Analytics 4’s server-side implementation is now standard practice for enterprise organizations, with Segment, mParticle, and RudderStack dominating the customer data infrastructure layer. The shift isn’t just technical; it’s strategic. CMOs now discuss “data sovereignty” and “measurement resilience” in board meetings, topics that would have drawn blank stares in 2024.

The cookie deprecation saga finally concluded in late 2025 with Chrome’s full third-party cookie sunset, making this transition from aspirational to mandatory. Organizations that delayed server-side implementation faced immediate measurement blind spots and attribution collapse. The winners were those who treated this as a three-year transformation program, not a last-minute technical fix—building first-party data strategies, establishing identity resolution frameworks, and creating organizational alignment around data governance.

What’s surprised most practitioners is the renaissance of contextual targeting. With behavioral tracking constrained, advertisers rediscovered that content context, purchase intent signals, and cohort-based targeting deliver surprisingly strong performance—often matching or exceeding the precision of deprecated third-party cookies. The industry is learning an uncomfortable truth: much of the hyper-targeting complexity was solving for measurement limitations, not driving incremental value. The future is both more privacy-respecting and more effective than the surveillance-based past.

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