Contact Builder Best Practices

Use a Single Contact Key

Contact Builder uses a single contact key value to identify a contact within a Marketing Cloud Engagement account. This value is identical to the subscriber key in Email Studio. Use the contact key value to assign information from several communication channels, such as mobile numbers and email addresses, to a single contact record. Follow these best practices to implement a unique contact key for each contact.

• Use a unique value that doesn’t relate to a specific channel. If you import a value from an external data source, use a string-based field, even if the external data source uses a number as the unique identifier. If you use your Engagement account to gather data, consider using a GUID or other generated ID in a string field as the contact key value.
• Use a contact key value that doesn’t change based on customer behavior. For example, a physical address isn’t a good contact key value, because it can apply to several people and can change frequently.
• To maintain consistent contact information and implementation, use the subscriber key value in Email Studio as your unique contact key value in Contact Builder.
• When you import information from an external information source, use the unique identifier from that system as your contact key to ensure consistent data imports. If your unique customer identifier is a numerical value, use a string-based field for the contact key when you create the data extension with information from the external data source.
• Contact key values can’t contain these characters.
  • ~
  • !
  • #
  • $
  • %
  • ^
  • &
  • *
  • (
  • )
  • -
  • +
  • }
  • {
  • /
  • \

Find Consistent Information to Tie Potential Duplicate Contact Records Together

You can’t merge or de-duplicate contact information in Engagement, so one contact can be represented many times. For example, a contact can include an email address in Email Studio and a separate device ID in MobilePush. Use a different value to help de-duplicate this contact via an external service or partner. Elimination of duplicate records keeps your contact count lower, reduces billing costs, and maintains the integrity of a unique contact record for marketing activities.

Understand the Difference Between All Subscribers and All Contacts Lists

The All Contacts list includes all contacts in an Engagement instance. The All Subscribers list specifically refers to subscriptions created within Email Studio. Email Studio references the All Subscribers list to prevent sends to unsubscribed email addresses. However, this action applies only to Email Studio information and activities. A contact can unsubscribe from a subscription in Email Studio and still receive messages from other apps, such as MobileConnect or MobilePush.

By default, Contact Builder uses a different demographic source of information for each channel. The different demographic attribute groups displayed in Contact Builder contain this information. However, the unique contact key value used to identify a specific contact remains consistent for all channel apps. To use a single set of demographic information for all channels, create an attribute group in Contact Builder. Use that group as the source of information for your marketing activities. Make that attribute group available to all necessary users and copy to other business units within your account.

Understand the Contact Record Deletion Process

To honor opt-outs, we don’t delete contacts in most situations. While you can delete contacts related to Email Studio, this deletion doesn’t completely remove their information from Engagement. We retain this information to make sure that the appropriate email addresses don’t receive any further messages after unsubscribing.

Change ID Number Data Type Before Linking to Contact Key

If you use a numeric value to identify individual contacts, change the data type to a string data type before you link it to Contact Key. You can’t directly link numeric values to Contact Key. For best performance, change the data type for your numeric identifiers before you import contact information into Contact Builder. To avoid performance issues, don’t link numeric identifiers and the CustomerID.

Link Attribute Groups and Populations Using Contact Key When Possible

Link attribute groups and populations using the contact key value. Don’t link using an email address field when the Contact Key or Subscriber Key value is available. If your use case requires you to create a link using the email address, create a text attribute that contains the email address and link using that value.

Understand the Differences Between Contact ID and Subscriber ID versus Contact Key and Subscriber Key

These system fields don’t serve the same purpose in Marketing Cloud Engagement.

Most customers use a primary identifier for their customers and link their identifier to Engagement using the Engagement Contact Key or Subscriber Key value.

The Contact ID and Subscriber ID fields act as surrogate keys used by internal Engagement systems. You can see these fields in tracking extracts and system data views in Query Activities. To avoid performance issues, don’t use these values for Engagement activities.

Limit Populations to Three Entities

Use populations to create large and distinct subgroups of your contacts, then segment contact records from there. For example, a doctor’s office creates populations for staff, for patients, and for vendors. If you create populations in your account, limit those populations to three or fewer to improve performance.