“Wherever there are companies that have a fair amount of first-party data that they can either match with CRM onboarding or that the platform can leverage their own first-party data for audience segmentation, targeting and closed-loop reporting, that’s where you’re gonna see the dollar shift,” Eng said.

The change in inputs will lead many platforms to move towards more algorithmic, data-driven models for attribution. For measurement, new methods will likely not be as robust, leading companies to rely on more inference and probabilistic modeling. It will be harder to inform optimization, possibly driving companies away from real-time signals towards more manual optimization, she explained.

“I hope publishers don’t believe false messiahs ... because I think they may get caught short if they do when third-party cookies are deprecated.”

Mike Woosley

COO, Lotame

However, investing in more first-party data is not a panacea that can replace third-party cookies. First-party data may prove to have less or different value to other companies in the advertising supply chain due to the way individual publishers define their audiences. For example, one publisher could identify a consumer as a sports enthusiast, but whether that consumer is interested in biking or surfing could dramatically affect an ad buyer’s interest — additional signals that might be missing from the publisher’s first-party data.