Email Segmentation

Why segment an email base

A mass send to the whole base is fast but ineffective. A premium-brand buyer receives a message
about a 70% off sale and unsubscribes. A newcomer with no purchases receives thank you for your
loyalty and is baffled. The result: a damaged domain reputation, more spam complaints, a falling
sender score.

Email segmentation solves this by splitting the base into groups with different content. The same
send date, different messages. The outcome is a higher open rate, fewer unsubscribes and more
attributed revenue per message sent.

The main types of segmentation

RFM — the foundation of e-commerce segmentation

RFM segmentation splits the base along three dimensions:

• Recency — how long ago the last purchase was
• Frequency — how often they buy
• Monetary — how much they have spent

VIP segment:       R=1, F=5, M=5  -> priority, exclusive access
At-risk segment:   R=4, F=4, M=4  -> reactivation with an offer
Dormant segment:   R=5, F=2, M=2  -> win-back campaign or removal

Tip: dormant users who have not opened a message for 6+ months are better moved into a
separate reactivation branch with a single message. No reaction — remove them from the active
base. That lifts deliverability and sender score for every other segment.

Common mistakes

• Too many segments. Twenty micro-segments on a base of 10,000 means samples too small for
  statistically significant tests and a content production load that is too heavy. Start with 3–5.
• No exit from a segment. A user who has stopped being dormant keeps receiving reactivation
  messages although they have already bought. Use dynamic segments with an exit condition.
• Segmentation without content personalization. Five segments created, identical messages sent.
  The minimum personalization is the subject line and the recommendation block.