Why is the audience count in my Customer Journey different from the number shown in the Segment calculator?

You may notice a difference between the audience size displayed in a Customer Journey and the number you see when calculating the same segment. This is expected behavior and occurs because these two features count entities differently.

Here's a breakdown of the difference:

• Segment Calculator: The number shown when you calculate a segment often represents the count of unique devices (identified by a Hardware ID or HWID) or specific contact points (like push tokens or email addresses) that meet the segment's criteria.
• Customer Journey: A Customer Journey operates based on unique users (identified by a UserID). A single user can be associated with multiple devices or contact points. For example, one user might have your app on their phone and also be subscribed to your emails.

When a Customer Journey starts, it correctly includes all unique users from the selected segment, regardless of whether they are reachable via a mobile device, email, or both. This means the Journey's audience count reflects the total number of unique individuals being targeted, which can be different from the count of just devices or contact points shown in the segment view.