The need for comprehensive identity resolution has been a challenge for the ad industry for some time. We heard a lot about people-based targeting, but has been always designated as a buy-side problem.
The upcoming end of 3rd-party cookies (3PC) and the increased demand of 1st-party audience data by buyers mean that publishers need alternative mechanisms to help advertisers find their audiences.
Once cookies disappear, the Universal ID is projected to be a backbone for targeted adv: it is a user identifier based on deterministic matching (not all of them though), that provides a shared identity to identify the user across the supply chain without syncing cookies.
Typically, to create a Universal ID from scratch a pub can integrate via an ID provider’s API using Prebid (which is offering identity modules that connect to identity providers).
Currently, most shared-ID solutions allow to store IDs in a 3PC, but 1st-party and offline data can also be used to create IDs (some call them tokens).
Now, many AdTech and trade groups are building Universal ID solutions – even if identity should be controlled by the pub and the end user, not by them.
However, adoption is often the biggest challenge, as Universal IDs are not yet available in the bid-requests at scales.