Why a cooldown period is needed

In e-commerce several triggers can fire on the same user at once: an exit-intent popup, a
personalized banner, a push notification about an abandoned cart, a welcome offer for newcomers.
Without a cooldown period the user receives all of it in a single visit — which very often ends in
an unsubscribe or a block.

A cooldown period answers the question: which message to send next, and when, when there are
grounds to send several.

Cooldown levels

In mature marketing systems the cooldown operates on several levels:

Level What it limits Example
Global Any communication to the user No more than 1 message every 4 hours
Channel One channel type Push — no more than once every 12 hours
Campaign One specific scenario Abandoned cart — no more than once every 48 hours
Thematic A group of similar campaigns All welcome scenarios — no more than once every 7 days

Tip: start with the global cooldown, then add the channel level. The campaign level is needed
for scenarios with a high risk of repeat firing — an abandoned cart, for instance.

Cooldown and prioritisation

When a cooldown blocks a send, the system has to know what to do next: defer the message, replace it
with another or skip it. The typical strategies:

  • Queue and delay — the message is queued and sent once the cooldown expires.
  • Priority-based — out of several queued messages, only the highest-priority one is sent.
  • Drop — some messages (urgent events, promotions with a deadline) lose their meaning once the
    cooldown expires and are simply cancelled.

Cooldown versus frequency capping

Both mechanisms curb intrusiveness, but in different ways:

  • Cooldown is a time buffer: no sooner than N hours after the last send.
  • Frequency capping is an impression limit: no more than N times in 7 days.

A well-designed system uses both. Frequency capping stops five impressions accumulating over a week;
a cooldown stops three of them going out inside a single hour.