Server-Side Tracking | EARNST

What is server-side tracking?

Third-party cookies are blocked by browsers. Ad blockers filter JavaScript tags. ITP shortens cookie lifetimes to 7 days or less. The consequence: incomplete data, inaccurate conversion numbers, poor campaign performance. Server-side tracking solves this by routing data through your own infrastructure. First-party cookies stay intact, tracking requests look like normal API calls, and you maintain full control over what data flows where and when.

The critical difference with EARNST: we run the GTM Server Container on our own infrastructure, not on Stape, not on Google Cloud. This sounds like a detail but it changes everything. Own infrastructure means true first-party cookies modified at the server level. It means custom modules that would not run on any hosted platform. And it means API-based conversion attribution instead of error-prone browser pixels.

Why own infrastructure instead of Stape or Google Cloud?

Standard setups on Stape or Google Cloud Run work for simple use cases. But they have clear limitations: you cannot modify cookie attributes at the OS level, cannot install custom modules, cannot create custom endpoints. You are bound by whatever configuration options the provider exposes.

On your own infrastructure, you control the entire stack. This enables true first-party cookie modifications via HTTP response headers. Not the JavaScript-based cookie setting that most agencies sell as "first-party" and that browsers still restrict. Server-set cookies with customized lifetime, correct domain scope, and SameSite flags that browsers treat like any other first-party cookie on your domain.

You can also build custom logic: data validation before forwarding to platforms, enrichment with CRM data, custom endpoints for specific use cases like offline conversions or phone attributions. These are not theoretical advantages. These are the capabilities that make the difference between a 15% ROAS uplift and a 35% ROAS uplift.

API-based conversion attribution instead of browser pixels

Most tracking setups still rely on browser pixels for conversion measurement. The problem: pixels get filtered by ad blockers, restricted by browser policies, and fail to fire when users leave the page too early. Every lost conversion means a missing optimization signal for the campaign.

We use API-based attribution. Conversion data is sent server-side directly to the APIs of Google Ads, Meta, TikTok, and other platforms. This happens completely independent of the user's browser. No ad blocker can prevent it. No ITP can distort the data. Attribution is more reliable, conversion numbers are more complete, and campaign algorithms receive better signals for optimization.

Meta CAPI, Google Ads Enhanced Conversions, and TikTok Events API are implemented in parallel, with event deduplication to prevent double-counting. This gives you consistent conversion data across all platforms.

Phone tracking and call attribution

For many businesses, 30% to 50% of conversions happen over the phone. Without call attribution, this share is completely missing from your campaign data. You optimize your ads based on incomplete data and wonder why certain campaigns appear to underperform.

We implement phone tracking that attributes calls to specific campaigns, keywords, and ads. Call data flows into the same attribution as your online conversions. Google Ads receives the offline conversion signal, Meta gets the CAPI events. The result: a complete picture of campaign performance that unifies online and offline conversions.

Custom CMP instead of off-the-shelf solutions

Cookiebot, Usercentrics, OneTrust -- these tools cover standard requirements. But they are also rigid: they use someone else's design, someone else's logic, someone else's servers. Any customization beyond the built-in options is either impossible or expensive.

We develop custom consent management solutions tailored precisely to your requirements. Custom design that integrates seamlessly with your website. Custom consent logic that maps exactly the granularity you need. Full control over consent signals forwarded to the server container and downstream platforms. Consent Mode v2 is natively supported.

If an existing CMP makes sense for your situation, we integrate it. The decision is based on your use case, not on our convenience.

Who needs this?

Any business running paid advertising or relying on analytics for decision making. This is especially critical for companies operating in Europe where GDPR requires explicit consent before setting most cookies. Server-side tracking on own infrastructure allows you to maintain measurement capabilities while fully respecting user privacy choices. It is also essential for e-commerce businesses where accurate conversion tracking directly impacts campaign performance and profitability.

If your marketing team reports declining conversion rates despite consistent performance, if phone calls are missing from your attribution, or if your CMP causes more problems than it solves, our approach is the answer. We work closely with your marketing and legal teams to align technical implementation with regulatory requirements.

How EARNST approaches it

We start with an audit of your current tracking implementation: which tags fire, which events are tracked, where the gaps are, which conversions are being lost. Then we set up the GTM Server Container on dedicated infrastructure, configured on a subdomain (for example, tracking.yourdomain.com). All relevant tags are migrated server-side.

Cookie configuration happens at the server level: HTTP response headers instead of JavaScript. API integrations to Google, Meta, and other platforms are set up with proper event deduplication. Phone tracking is implemented when calls are a relevant conversion channel. The CMP is either custom-built or existing solutions are cleanly integrated.

Every implementation is fully documented. You receive an event matrix showing which events fire when, with which parameters, and to which systems. This is important not only for GDPR audits but also for future adjustments. After go-live, we monitor in parallel for two weeks, compare old and new data, and fine-tune as needed.

Project scope

A standard server-side tracking implementation takes 2 to 3 weeks: 1 week for audit and concept, 1 week for implementation and testing, 1 week for monitoring and optimization. More complex setups with phone tracking, custom CMP, or multi-domain tracking may take 4 to 6 weeks. You need access to DNS (for subdomain setup), Google Tag Manager, and the relevant advertising accounts. The server container runs on dedicated, own infrastructure.