Understanding EUID and User Identifiers in CDP
1. What Can EngageLab CDP Achieve?
EngageLab CDP (Customer Data Platform) helps businesses integrate multi‑platform user data and build complete user profiles through unified identity resolution. It effectively resolves complex identity recognition scenarios—such as multiple devices and accounts, single accounts across multiple devices, or multiple accounts on a single device—enabling a complete marketing loop.
2. What Are User Identifiers in CDP?
Different IDs across various business platforms or stages may identify users. User identifiers refer to the identity IDs used by users in different business platforms or phases. CDP consolidates the following three types of identifiers to build a unified user data asset:
| Identifier | Priority | Description & Type |
|---|---|---|
| user_id | 1 (Highest) | Set when a user logs in with a unique login identifier. Only 1 value is allowed. |
| anonymous_id | 2 | Set when the user is not logged in but provides other identifiable information (e.g., email, third‑party ID). Only 1 value is allowed. |
| registration_id | 3 | Automatically generated by EngageLab SDK after integration in App/Web, identifying the end‑user device. Multiple values are allowed to support multi‑device scenarios. |
3. What Is EUID in CDP?
EUID (EngageLab User ID) is the unique identifier assigned to each user by the EngageLab MA CDP system, generated based on user identifiers and their priority relationships. The generation logic is as follows:
1. Request Initiation
The business side initiates a request to set one or more of the above 3 user identifiers.
2. Priority‑Based Matching
The system matches the provided identifiers in the user database from highest to lowest priority:
- If the highest‑priority identifier matches successfully, the corresponding EUID is returned.
- If any identifier matches, matching of lower‑priority identifiers stops.
- If a lower‑priority identifier matches while higher‑priority ones do not:
- If that EUID is already bound to a higher‑priority identifier, a new EUID is generated (e.g., when the same device switches accounts).
- If no higher‑priority identifier is bound, the original EUID is returned (e.g., when the same anonymous user visits multiple times).
- If all identifiers fail to match, a new EUID is generated.
3. Identifier Ownership Processing
The system ensures that the same user identifier belongs to only one EUID at any given time:
- The system traverses the user database with the provided identifier values and removes any existing bindings of those identifiers in other EUIDs.
- All provided identifier values are written to the EUID’s identifier fields. The processing logic (overwrite or append) depends on the data type.
Example: The same device cannot have user identifiers belonging to both EUID‑A and EUID‑B.
Through this mechanism, EngageLab CDP accurately recognizes user identities even in complex scenarios, providing a reliable data foundation for automated marketing.
