Data Modeling and Management21% of the exam
Contact key choice, billable contacts and Contact Delete
What a contact key choice costs or breaks: stable, channel-free keys, subscriber key behaviour and migration, how billable contacts are counted, what creates contacts without channels, and how to clean them up safely with Contact Delete.
Evaluate implications on data model when choosing contact identity.
~8 min read · 21 practice questions ·
What the exam expects
- Recommend a contact key that is unique, channel-free, stable and safe to expose, and reject keys that break those rules.
- Explain how the subscriber key drives All Subscribers, repeated addresses, preference updates and tracking exports, and what a migration to subscriber keys requires.
- Calculate billable contacts and explain where email and mobile identities are managed in Enterprise 2.0.
- Diagnose what created contacts without channel addresses from the key format and the feature in use.
- Plan a safe Contact Delete cleanup.
- Explain the Contact Delete phases, where deletion is enabled and what it leaves for the customer.
- Key terms: contact key (single value identifying a contact account-wide, identical to the Email Studio subscriber key); billable contact count (de-duplicated union of All Contacts, populations and hidden triggered send lists); channel-less contact (in All Contacts with no email, mobile, push or LINE address); hidden managed list (where triggered sends keep recipients not added to All Subscribers); Contact Delete (process that deletes contacts across all subscriber types).
Key facts
Subscriber key length
- Detail
- 254 English characters
Data obscurity
- Detail
- Subscriber key is the only field not encrypted
Disallowed characters
- Detail
- Hyphen on one page, @ on the other
Merging contacts
- Detail
- Not possible in Engagement
Subscriber key migration
- Detail
- Up to one week with no sends or imports
Billable count
- Detail
- All Contacts + populations + hidden lists, de-duplicated by key
Email vs mobile scope
- Detail
- All Subscribers at EID level; mobile at business unit level
Synced records without a channel
- Detail
- Modified date 01/01/0001 12:00 AM
Contact Delete suppression period
- Detail
- 2 days by default; set in days under Manage Settings
Non-sendable data extensions outside a population
- Detail
- Not reached by Contact Delete
Contact Delete scope
- Detail
- Deletes all subscriber types
Sources for this section (8)
- Subscriber Keyhelp.salesforce.com (opens in a new tab)
- Contact Builder Best Practiceshelp.salesforce.com (opens in a new tab)
- Identify Unique Subscribers Using Keyshelp.salesforce.com (opens in a new tab)
- Contact Countshelp.salesforce.com (opens in a new tab)
- Contact Definition and Count Determinationhelp.salesforce.com (opens in a new tab)
- Contact Deletionhelp.salesforce.com (opens in a new tab)
- Enable Contact Deletehelp.salesforce.com (opens in a new tab)
- Permanently remove Contacts or Subscribershelp.salesforce.com (opens in a new tab)
- Which modified date do synchronized records without a channel show?
- When does a child business unit show contact counts in Enterprise 2.0?
- Why can Journey History fail to show which journey created an older channel-less contact?
- How can a MobilePush app avoid creating anonymous contacts before login?
The questions are free to read. Answers with their sources and self-grading are included with the pack.
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