Measuring the ‘Halo’ ad effect: why it’s CMM's time to shine in a post-cookie world

Rishi Saxena, Global Product Lead, WFA, describes how Cross-Media Measurement is pioneering privacy-safe advertising across a broad range of digital advertising channels.

The fragmented world of programmatic advertising provides an analogy that reflects digital advertising’s broader issues regarding measurement and – importantly – privacy. 

With numerous measurement products and services offered by various providers and platforms, the growing number of solutions for different channels - each with their own take on new and old metrics - is bewildering and complicated in an era of ever-shifting consumer behaviour.

The demise of the cookie heralds the arrival of the privacy-first era, in which legislation is (rightfully) putting greater emphasis and importance on consumer privacy. So, there are significant challenges for advertisers looking to target consumers in a privacy-first way while simultaneously understanding how their campaigns are performing across different channels. 

Cross-Media Measurement (CMM) is emerging as the front-running solution that will help advertisers do just that, and the process comes with supplementary benefits. That’s because CMM’s scale offers enhanced campaign optimisation opportunities and, therefore, advertising effectiveness, all while providing a multidimensional view of an audience that helps target consumers more effectively. 

Privacy-first: the state of play

Yet, the ability to target consumers over a variety of advertising channels in a privacy-compliant way remains a huge challenge for advertisers, publishers, and the broader digital advertising industry. Stripping identifying information from data sets has become standard practice, but a study by the Massachusetts Institute of Technology has shown that with a few extra data points, previously anonymised data can become identifiable again. 

Therefore, despite all the progress that has been made in recent years to protect consumer privacy, there is still much work to be done. Even Trusted Execution Environments (TEEs) – a secure space commonly used in digital advertising to hold and process consumer data – have proved undesirable due to a concern surrounding single-point failures. 

The solution to our industry’s privacy concerns is proving to be encryption. This technology has been successfully used in many industries, including the financial sector, and is key to ensuring CMM can safely target an audience.

Encryption in Cross-Media Measurement

Here at the WFA, we’re developing our own CMM solution, Halo. This framework offers the latest cryptographic technology, combining high accuracy in audience targeting with the ethical considerations that characterise the industry's focus on privacy-first advertising. 



But Halo aside, encryption will be important for all CMM platforms going forward. As we've seen with TEEs, many industry-standard technologies can’t provide consumers with the protection and privacy their data deserves. To that end, CMM solutions should be looking at the likes of Multi-Party Computation (MPC) and Differential Privacy (DP) as encryption solutions to their privacy problems.

MPC is widely used in the finance sector. While intensive from a computational perspective, it enables multiple parties to compute data simultaneously without exposing their datasets. MP was made popular by Google, which uses the technology to protect the privacy of those using its Chrome browser. The technology analyses a data set, collecting trends, information and insights while protecting the personal information of individual users. 

These encryption technologies can be combined and processed using advanced models to develop anonymised digital profiles and build rich, detailed audience insights without compromising individual information.

Privacy’s future in CMM

CMM solutions can advance the digital advertising industry towards becoming a privacy-first sector. As these platforms embrace encryption, there will be a shift in how advertising campaigns are measured across a range of media channels.

It is CMM’s access to vast data sets from different channels that is a key strength and sets it apart from alternative measurement and analysis tools. The breadth of information it has access to will allow advertisers to take advantage of truly integrated media measurement, which is inherently privacy-complaint and extremely effective.

Also published in: Performance Marketing World