Issue

In Segment Engage, the audience size displayed is significantly smaller than the number of users who meet the qualifying trait in the warehouse. Users who should qualify for the audience based on the trait (e.g., consents_cookie.marketing = true) are not included in the audience membership.

Product

Segment Engage

Environment

Segment Console

Cause

A mismatch in trait naming or structure can prevent users from being included in the audience. Segment flattens nested traits, so traits like consents.cookie_marketing and consents_cookie.marketing may be treated as the same underlying field. If the old trait structure is present, updates to the new structure may be ignored. Additionally, external processes such as Reverse ETL syncs can overwrite or nullify audience membership traits, removing users from the audience.

Resolution

1. Ensure trait naming and structure are consistent across all sources and mappings.
2. If migrating to a new trait structure, first nullify the old trait before updating to the new one.
3. Review and update any Reverse ETL or warehouse syncs to avoid overwriting audience membership traits.
4. After correcting trait structure and syncs, re-trigger audience evaluation by updating the relevant traits to ensure users are correctly included.

Additional Information 

Trait path conflicts and sync overwrites are common causes of audience membership discrepancies. Always verify trait mapping and sync logic when troubleshooting audience size issues.