In Email Studio, what is used to uniquely identify individuals with a value defined by...

In Email Studio, the Subscriber Key is used to uniquely identify individuals. Defined by the admin, it allows for unique tracking of subscriber engagement and prevents duplicate records. Subscriber Key can be an email address, customer ID, or any other unique identifier.

Importance of Subscriber Key: It provides a unique identifier for managing subscriber data, enabling detailed personalization and tracking across the platform.

Salesforce Documentation Reference: For more on Subscriber Keys, refer to Subscriber Key Usage in Email Studio.