Data 360: 'SFMC Subscriber' Data Stream Contains More Records Than All Subscribers list in Marketing Cloud

When you setup a Marketing Cloud connector to integrate Customer Data 360 with a Marketing Cloud account, you can choose to setup the Marketing Cloud Starter Data Bundles in Data 360.

The contact data bundle includes data streams such as SFMC Subscriber, which ingests contact-related records from Marketing Cloud into your Customer Data 360.

Please note that the SFMC Subscriber data stream does not source its records from the All Subscribers list in Email Studio but ingests contact records that are present on All Contacts list in Contact Builder. As a result, you may see that the number of records in your SFMC Subscriber data lake object is significantly greater than the count of subscribers showing in your All Subscribers list.

This is possible because a Marketing Cloud contact can exist in your All Contacts list in Contact Builder that if the contact is not an email subscriber they will not exist on All Subscribers list in Email Studio. As outlined in Find and Delete Soft-Deleted Email Studio Contact, it is also possible to delete a subscriber from All Subscribers list. This removes a subscriber from All Subscribers but does not remove the subscriber as a contact in All Contacts. In both these scenario, you can expect to see a contact ingested into Customer Data Platform via the SFMC Subscriber that does not exist on the All Subscribers list.