Case Study SunStyle: From 35% Data Loss to 99% Reliability with HubSpot and Server-Side

Published by Thomas dans la catégorie Practical Cases Last update : 21.01.2026 à 20h19


Table of content

In brief (Summary for the busy):

  • The Client: SunStyle, a leader in solar tiles (High-Ticket B2B/B2C).

  • The Problem: Compliance (CMP Complianz on WordPress) blinded the Ads campaigns (-35% data).

  • The Solution: A hybrid architecture of Server-Side Tracking + HubSpot API (CRM).

  • The Results (1 year): Data reliability at 99%, CPA reduced by CHF 33.- and +312 conversions generated.

1. The Context: When Compliance Breaks Performance

SunStyle sells cutting-edge technology: aesthetic solar roofs. The sales cycle is long, the average basket is high, and each lead is worth gold.

Their site, powered by WordPress, had to comply strictly with the nFADP and GDPR. The team deployed the cookie management solution Complianz.

The immediate shock: As soon as the cookie banner was activated, the dashboards went dark.

  • Between cookie refusals, AdBlockers, and browser restrictions (ITP), the gap between actual leads (in the CRM) and visible leads (in Google Ads) rose to 35%.

  • Consequence: The Google Ads algorithm, deprived of a third of the data, began to poorly optimize bids. The cost per lead increased.

This is where A-Track intervened.

2. Phase 1: The Urgency of Server-Side Tracking

Our first intervention was to keep our head above water. We could no longer rely solely on the client's browser (Client-Side), which is vulnerable to blockers.

We deployed a GTM Server-Side infrastructure. Instead of sending data from the visitor's browser, we routed it through a secure server controlled by SunStyle.

Intermediate result: The data gap decreased from 35% to 12%. It was better, but for an industrial player like SunStyle, losing still 1 lead out of 10 remained unacceptable for budget management. Perfection was the goal.

3. Phase 2: The

Are you using HubSpot or Salesforce and your Ads data doesn't match?

As with SunStyle, we can reconcile your tools and ensure reliable management.

Request a CRM/Ads connection audit

Questions fréquemment posées

Does CAPI work without cookies?

Yes, it transmits events from the server, respecting user choices.

Is it illegal to use Google Analytics in Switzerland or Europe?

No, it is not illegal per se, but the default configuration poses problems. It is essential to anonymize IPs, reduce data retention, and ideally, use a proxying via a Server-Side tracking to prevent the user's IP from being directly exposed to Google's American servers.

What is GTM (Google Tag Manager) Server-Side?

It is the server version of GTM. It allows for receiving web data, manipulating it (cleaning PII, hashing emails), and distributing it to partner APIs (Meta, Google Ads, TikTok).

What are Google's "Enhanced Conversions"?

This involves sending hashed first-party data (email, phone) to Google during a conversion. This allows Google to identify who converted even if the cookies have been cleared.

What is Google Consent Mode v2?

It is a mechanism that allows your Google tags (Analytics, Ads) to adjust their behavior based on the user's choice on the cookie banner. It has been essential since March 2024 to maintain advertising functionalities.