A company wants to capture both customer_id and email_address as identities in their data feeds...

In Adobe Experience Platform,Identity Namespacesare used to categorize the types of identities that distinguish an individual across various channels and devices. When modeling data for theReal-Time Customer Profile, selecting the correctIdentity Typeis fundamental for accurate profile stitching and the integrity of the identity graph.

customer_id (Cross-Device ID):A customer_id is typically an internal, durable identifier assigned by a brand (such as a CRM ID or Loyalty ID). Since this ID remains constant regardless of the hardware or browser the user utilizes, it is classified as aCross-Device ID. This classification allows the Identity Service to link multiple device-specific IDs (like ECIDs) to a single, stable person-level identifier, facilitating a unified cross-channel view.

email_address (Email):For an email address, the recommended type isEmail. This is an out-of-the-box identity type optimized for handling string-based email identifiers. It is often the primary key used for marketing orchestration and cross-device identification when a user authenticates.

UsingCookie IDorDevice IDfor a customer_id would be technically inaccurate, as those are transient or hardware-bound.Person IDis a conceptual term rather than a standard identity type used for internal CRM IDs in the platform's namespace configuration. By correctly assigningCross-Device IDto the internal ID andEmailto the email field, developers ensure that the Identity Service can effectively perform "identity stitching" to merge data fragments into a cohesive profile.