Dormant customers are the cheapest addressable audience most businesses hold and the one they contact least systematically. The economics differ from acquisition in specific ways.
The identification cost is already paid
Acquisition spends money to find someone and establish that they are relevant. For a lapsed customer both facts are already known and recorded.
Contact is therefore possible through owned channels at near-zero marginal cost, which changes what response rate is required to justify the activity.
Purchase history also allows the message to reference what the customer actually bought, which no acquisition channel can do at first contact.
Response declines with elapsed time
Recency is the strongest predictor in most direct marketing models. A customer inactive for a few months behaves very differently from one inactive for years.
The decline is steep rather than gradual, so a program that treats all dormant records identically spends most of its effort on the least responsive part of the file.
Segmenting by time since last purchase, and by prior frequency and value, concentrates effort where the probability still exists.
Why they left determines what works
Customers lapse for different reasons: a service failure, a price increase, a life change, a competitor, or simply no current need.
A discount addresses only the price case and gives margin away to everyone else, including those who would have returned when the need recurred.
Where a service failure is recorded, acknowledging it directly performs better than an offer, because the offer does not address the reason.
Discounting trains the behavior it rewards
Repeated win-back offers teach customers that lapsing produces a discount, and some will lapse deliberately to trigger it.
This is most visible in subscription categories where cancellation reliably produces a retention offer that regular customers never receive.
Varying the incentive, limiting frequency and offering value other than price reduces the training effect while keeping the program functional.
Deliverability constrains the whole exercise
Mailing a long-dormant list produces high bounce rates, spam complaints and low engagement, all of which damage sender reputation for the active file as well.
Sending in graded batches, beginning with the most recent and monitoring engagement before proceeding, limits that damage.
Consent requirements for email and text messaging differ, carry statutory penalties in the case of text, and change over time, so an old list should be checked against current rules before it is used.