Table of content
In Brief: the project at a glance
The client: Bordier-Schmidhauser, a real estate agency operating in the Geneva market (sales, valuation, property management).
The challenge: An urgent FADP compliance overhaul, while valuation forms were transmitting sensitive personal data to advertising platforms.
The result: Zero personal data sent in clear text to platforms, a cost-per-lead reduction in the range of 30 to 40%, and finally reliable attribution.
1. Geneva Real Estate: a Sector Where Data Is Ultra-Sensitive
When an owner requests a valuation of their apartment, they are not just filling out a form: they are entrusting strategic and personal information. Their identity, their address, the value of their property, and their intention to sell. In the canton of Geneva, all of this falls directly within the private sphere protected by the FADP.
For Bordier-Schmidhauser, trust is the foundation of the client relationship. As in any sector where discretion is paramount, two behaviors distort marketing measurement:
A high cookie refusal rate — often close to one visitor in two in this type of trust-driven sector.
A significant share of traffic on secure browsers (Safari, Firefox) that naturally limit tracking through ITP mechanisms.
2. The Diagnosis: Personal Data Sent in Clear Text to Ad Platforms
The initial audit revealed a problem far more serious than a mere loss of performance. The legacy client-side setup was leaking critical information:
Valuation form fields (name, e-mail, property address) were captured by tags and transmitted in clear text to Google and Meta.
Tags fired before consent was collected, in direct violation of the FADP and the GDPR for European prospects.
Lacking reliable measurement, Google Ads campaigns were flying blind on nearly half of the traffic.
The double risk: a genuine legal exposure (complaint, audit by the data protection authority) compounded by an advertising budget wasted for lack of reliable data.
3. The Solution: a "Privacy-First" Server-Side Architecture
A-Track deployed a server-side tracking architecture hosted on a Swiss server, designed first for compliance, then for performance.
A. The Filtering Gateway (Server-Side)
All data now passes through an intermediate collection server before any transmission to platforms:
Removal of personal data: name, property address, and other sensitive information never leave the client's infrastructure.
Anonymization: IP addresses are truncated before transmission.
B. CMP and Consent Mode v2 in Advanced Mode
A compliant CMP was configured, coupled with Google Consent Mode v2. For visitors who refuse tracking, Google receives only anonymous, cookieless signals, allowing its AI to model lost conversions without ever tracking the individual against their will.
C. Enriched Conversions, but Compliant
Data sent to Google Ads and Meta (CAPI) is transmitted only in hashed form and after consent. The attribution benefit is preserved, without ever exposing an owner's real identity.
4. The Results: Compliance AND Performance
The project proves that compliance is not a constraint that slows marketing down, but a foundation that makes it reliable.
Compliance: no more personal data transmitted in clear text. Tracking now respects the user's choice, and documentation is ready in case of an audit.
Data reliability: recovery of a significant share of previously invisible conversions, in the range of 25 to 40% depending on the channel.
Cost per lead: a reduction in the range of 30 to 40%, as the Google Ads algorithm is fed cleaner and more complete data.
The ranges above correspond to typical orders of magnitude for a server-side deployment in a sector with a high refusal rate. Exact results vary depending on traffic and starting maturity.
5. Technical Focus: Recovering Safari Traffic (ITP)
In premium real estate, the share of Apple users (iPhone, Mac) is dominant. Without server-side, these visitors' cookies have their lifespan limited to 24 hours or 7 days by ITP mechanisms.
Thanks to secure server-side First-Party cookies, a valuation request can now be correctly attributed to a first visit made several weeks earlier — a decisive advantage when the decision cycle of a property sale is measured in months.
Conclusion: Compliance as a Competitive Advantage
The Bordier-Schmidhauser case illustrates a conviction at the heart of the A-Track approach: in a sector where trust is the primary asset, FADP compliance is not a brake, it is a commercial argument.
By securing its clients' data while making its campaigns reliable, the agency has turned a legal obligation into a controlled and sustainable growth engine.
