Definition
Segmentation turns customer data into an audience definition. A segment may use profile fields, subscription state, plan, geography, product events, purchase history, or message activity.
Static lists capture membership at a moment in time. Dynamic segments reevaluate rules as customer data changes. Both require explicit consent and suppression checks at send time.
Why it matters
Relevant targeting reduces unnecessary volume and makes content, timing, and calls to action fit the recipient’s current state. It also creates cleaner measurement than sending every message to the entire database.
How it works
- 01
Define the customer question the audience should answer.
- 02
Translate it into explicit inclusion and exclusion rules.
- 03
Preview membership and inspect edge cases.
- 04
Reevaluate at send time and apply global suppressions.
Example
subscribed_to = product_education
AND signup_at >= now - 14 days
AND first_campaign_sent_at IS NULL
AND account_status = active
EXCLUDE complained, unsubscribed, hard_bouncedCommon mistakes
- Building segments from unreliable or undefined fields.
- Forgetting exclusions and suppression scope.
- Creating dozens of tiny segments with no meaningful content difference.
- Using inferred sensitivity or protected characteristics carelessly.
Key takeaways
- Start with a customer state, not a clever query.
- Document field meaning and freshness.
- Preview the real people entering and leaving the segment.