Publisher User Account ID

A Publisher User Account ID is a high-quality, first-party identifier generated by a publisher when a user authenticates on their platform (e.g., by logging in or creating an account).

Key characteristics:

• Authenticated: It is explicitly linked to a verified user identity, typically an email address.
• Cross-Device Recognition: It allows the publisher to recognise the same unique user across different devices and environments within their own ecosystem.
• First-Party Value: This ID is considered a direct, privacy-compliant asset for the publisher, forming the foundation for personalised experiences, subscriptions, and sophisticated addressability strategies like SSO and Seller Defined Audiences.