For an identifier shared across siloes, which Identity Namespace type should be selected?

When considering the appropriate Identity Namespace type for an identifier that is shared across silos, the Cross-device ID stands out as the ideal choice. This is primarily because the Cross-device ID is designed to unify and associate user interactions across multiple devices, facilitating a seamless experience. It enables organizations to track a single user as they move between different devices and platforms, which is essential for creating a comprehensive view of user behavior and preferences.

The use of a Cross-device ID effectively supports integrated marketing strategies and analytics, allowing for better targeting, personalization, and customer journey mapping. This type of identifier is particularly valuable in today's multi-device environment, where users often switch between smartphones, tablets, and desktops.

In contrast, the other identifier types do not share the same cross-silo capability. A Unique User ID is typically restricted to a single user account, a Session ID is often limited to a specific interaction within a single session, and a Device ID generally identifies a single device rather than linking to a user across multiple devices. Therefore, when the goal is to establish a consistent identity across various user interactions and devices, the Cross-device ID is the most effective choice.