IAB Tech Lab finalizes first addressability solution

Project Rearc, an initiative within IAB’s Tech Lab, has announced the finalization of its first solution to the post-cookie addressability challenge, Seller Defined Audiences (SDA). The concept was first proposed in March 2021.

As the name suggests, this solution rests seller-side, enabling publishers or their data partners to scale first-party data in a privacy-compliant manner, aiming to “democratize the concept of audience cohorts for the open ecosystem” (from the Tech Lab release).

Publishers will be able to create and scale anonymous first-party data-based audiences across channels, including web, app and CTV. Audience members can be grouped using a standardized, but also customizable, Audience Taxonomy. Additionally, context- or content-based audiences can be created using a context taxonomy (yet to be standardized).

Among other benefits for buyers, it allows DSP machine-learning systems to optimize cohort selection through the availability of API-delivered metadata.

Why we care. It’s another addressability solution, this time rooted in the rich first-party data held by publishers. It holds out a best-of-both-worlds promise by offering audience-based and context-based addressability. And since it’s a Tech Lab initiative, it will continue to be an open and transparent work-in-progress.

The release admits “SDA makes no claims of being a silver-bullet for the industry, but should be a valuable tool in our toolbox.” A refreshing position to take because the air is full of supposed silver bullets right now.