SPH Media explores first-party data collaboration with Decentriq’s data clean rooms

The phase-out of third-party cookies presented SPH Media with more than just a technical challenge — it raised fundamental questions about the future of audience targeting. 

Without a privacy-preserving alternative, some publishers have already seen advertiser budgets shift toward walled gardens that could offer targeting at scale. 

For SPH Media, the opportunity wasn’t just to stem the tide, but rather to offer premium, privacy-respecting targeting to high-value partners.

At the same time, a leading global wealth manager (GWM) was looking to improve the precision of its advertising without compromising on regulatory compliance or customer confidentiality. And they weren’t interested in impressions or reach alone. They needed proof that privacy-respecting advertising could drive real user engagement, particularly in a category where trust and attention are hard-won: high-consideration financial products.

The two parties therefore shared a common objective: to reach the right audiences effectively and ethically while driving engagement with the brand.

To address this challenge, the GWM joined forces with SPH Media and Decentriq to conduct a privacy-preserving audience activation pilot. The pilot aimed to explore how publishers and advertisers could collaborate on first-party data without ever exchanging or exposing personally identifiable information.

The approach centered on Decentriq’s data clean room platform, which — thanks to use of Trusted Execution Environments (secure, hardware-backed enclaves that allow data to be used for specific computations without being visible to any party involved) — were able to uphold the rigorous compliance standards required for both collaborators.

Both SPH Media and the GWM uploaded hashed email addresses into the Decentriq platform. Within this secure environment, the clean room performed two key tasks:

1. Matching shared customers between the advertiser and publisher.
   
   
2. Creating lookalike audiences based on shared user traits.
   

At no point could either party access the other’s data, and even Decentriq remained blind to the inputs and outputs.

Once the lookalike list was created, SPH Media passed it to its data management platform and publisher-side ad server for audience activation. This privacy-first approach was reviewed by the Personal Data Protection Commission (PDPC), which confirmed that the design did not result in disclosure of personal data between the parties, affirming both technical and regulatory credibility.

The campaign was evaluated based on meaningful engagement: click-through rates and continued navigation on the advertiser’s site. To fine-tune performance, SPH Media and the GWM tested different configurations, adjusting two critical parameters:

• Audience freshness: how recently the customer data was updated.
  
  
• Lookalike size: the percentage of SPH’s user base included in the lookalike audience.
  
  

Through A/B testing, they discovered that smaller, more recent audiences performed significantly better. A configuration with a 30-day refresh rate and a lookalike segment of 3% yielded a 90% lift in engagement compared to broader, less current segments.

These results validated the hypothesis: privacy-preserving collaboration not only works, but can also outperform traditional methods when paired with smart audience strategies.

The success of this pilot project has paved the way for future data collaborations. SPH Media now has a proven path to deliver targeted advertising in a way that protects user trust and complies with local data protection law. For both the publisher and the advertiser, Decentriq’s platform demonstrated that privacy and performance don’t have to be a tradeoff — they can go hand in hand.