Managing ContactKey and SubscriberKey in Salesforce Marketing Cloud for Unified Contact Management

Question

I use a sendable Data Extension as an entry source for a journey. This DE contains SubscriberKey and EmailAddress, and we've configured the data extension settings so that SubscriberKey in the DE relates to SubscriberKey in SFMC (it was required).

My understanding is that when we send an email through this journey, a subscriber will be created, and they will appear in the "All Subscribers" list in Email Studio.

My question is: Will this subscriber also appear in "All Contacts" in Contact Builder with a ContactKey identical to the SubscriberKey from the DE used for sending? If so, why the SubscriberKey is not just called ContactKey?

I'm asking because we are implementing mobile push notifications and SMS in our project. We need to ensure that the same ContactKey is associated with the email, device ID (for push), and mobile number (for SMS) to avoid duplicating contacts. What is the best approach to achieve unified contact management under a single ContactKey across multiple communication channels in SFMC?

Thanks!

Answer 1

Yes, the Subscriber Key using in the journey DE will be the one show up in "All Contacts list" in Contact Builder.

A contact can be belong to one or multiple channels or even no channels.

When you send an email through the journey, you are registering the contact into the email channel. A (email) subscriber is always a contact (in All Contacts list) but a contact may be not belong to the email channel (not in All Subscribers list). So, the difference how you call it a Subscriber Key or a Contact Key, it depends on the context.

How to ensure that the same Contact Key is associated across the channels? Well, it's a broad question and depends on the situation you are facing. In general, if you have a SF CRM connecting with your MC, I would recommend that you use the CRM contact ID (prefix 003) as your subscriber key/contact key whenever possible.

Speaking of avoiding duplicating contacts. You can read more about the Contact Count in @Jonas's answer here.

Hope it will help.