Publisher Cohorts: Unravelling the Cookieless World

Publisher Cohorts: Unravelling the Cookieless World

In the dynamic digital media landscape, cookies have long served as the default technology for marketers to gather user data for personalised advertising and analytics. Apple’s Safari was the first to deprecate cookies and by 2024, Google Chrome will become the last major browser to phase out third-party cookies. While some alternative routes are already known, such as the importance of nurturing first-party data sources, others are still evolving. These include publisher cohorts, universal IDs, clean rooms, and contextual solutions, each presenting unique potentials in terms of privacy, scale, implementation ease, and longevity. In the months ahead, we embark on an exploration of these evolving replacement cookie solutions, providing our insights and perspectives to aid in navigating and adapting to the imminent changes in the digital marketing landscape.

This month, we will explore publisher cohorts.

Publisher Cohorts 

Rather than targeting users 1:1, publisher cohort targeting is when consumers are grouped together based on smaller groups. Instead of relying on personally identifiable information or demographics, publishers collect first-party data from user behaviours, interests, assessments, viewing habits, submissions, and more within a publisher’s environment. By leveraging machine learning, the technology analyses a user’s behaviour and assigns them to a cohort for targeting, built directly at the source by publishers.

Merkle's POV

To analyse this solution, we have investigated privacy, scale, ease of adoption and sustainability.


By grouping users into cohorts, publisher cohorts reduce the need for individual user tracking which aligns with evolving privacy regulation like GDPR.  Nevertheless, the success of cohort-based approaches for each publisher largely relies on the effectiveness of user identity protection measures and the potential risk of reidentification. Merkle’s best practice is to undertake a rigorous publisher audit to ensure that the data collected meets the standards of Merkle’s data collection policy.  


Scalability relies on a publisher's resources. Larger publisher networks (such as MailMetroMedia, Sky, or LAD Bible group) achieve broader scale, capitalising on their breadth of networks and their current data collection infrastructure. In contrast, independent publishers like dailymotion are likely to see breadth of scale as a challenge but may provide superior depth of data due to specialised networks.  At Merkle, we collaborate with clients to analyse their goals, target audience and marketing objectives to make informed decisions that strike the right balance between precision in reaching the right audience and reaching them at scale. Through our partnership with the Conscious Advertising Network (CAN), we strive to diversify our media buying to support publishers which promote independent voices and communities. This ensures that brands not only reach their desired audience but also contribute to a positive and diverse media ecosystem.


The publisher cohorts solution offers relative ease of implementation for advertisers. Advertisers can more readily engage with cohorts defined by publishers, reducing their dependence on complex third-party tracking or data-gathering methods. Ensuring seamless integration and coordination between publishers and advertisers will be crucial to maximising the ease of adoption.


Ultimately the long-term sustainability of any cookie-less solution will be at the mercy of its trustworthiness for both consumers and advertisers. We believe that publisher cohorts carry little risk of losing trust as all user data stays with the publisher and does not get leaked in the bid-stream. Its longevity will however be challenged by the power of emerging identity-based solutions like Universal IDs and clean rooms and their ability to match advertiser and publisher data safely in the eyes of privacy to enhance targeting across publishers or platforms.


Publisher cohorts represents a low-risk strategy and a shift towards a more privacy-conscious and responsible future. While challenges in scale, longevity and disparities between publishers persist, the industry's commitment to safeguarding user privacy and fostering innovation offers a promising path forward. By prioritising these principles, we can shape a digital ecosystem that respects user choices, drives advertiser success, and supports the diverse voices of independent publishers.

For publishers concerned about scale:Reach larger audiences with your cohorts. Contact Merkle to maximize ROI.

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