Birthday and Anniversary Emails: Triggered Celebrations

Date-triggered emails are the easiest automated flow to build and the one whose value is most often assumed rather than measured. They perform well in aggregate reporting for a reason that has little to do with the occasion: they go to a self-selected group who cared enough to supply a date.

That does not make them worthless. It makes the comparison worth doing properly before adding a field to a form.

The anniversary you already have

Every subscriber has a signup date, recorded automatically, accurate, and available for the entire list rather than for the minority who filled in a birthday field.

A message on the anniversary of joining — a year of reading, here is what you might have missed, thank you — reaches everybody and costs no form completions to enable.

It also suits businesses where a birthday makes no sense. A subscriber to a deliverability newsletter has no particular reason to hear from you on their birthday, and an offer attached to it reads as a device rather than a gesture.

Timing: before, not on

An offer arriving on the day is usually too late to be used for the occasion, particularly where anything has to be delivered.

Somewhere between a week and a fortnight ahead is the workable window for anything transactional, with the message framed as being in advance rather than as a mistake.

For an anniversary message with no offer attached, the day itself is fine — there is nothing to act on and the timing is the point.

The mechanics that catch people out

The twenty-ninth of February. A birthday field can hold it and three years in four it does not exist, so the rule needs to say explicitly what happens — usually the twenty-eighth.

Missing and default values. A birthday field left empty, or filled with the first of January by a form default, produces either nothing or a large batch of messages on one day. Check the distribution before switching the flow on; a spike on a single date is the signal.

Time zones, if the flow fires at midnight. A subscriber several hours ahead receives their birthday message the day before, which is a small oddity that recurs annually.

Measuring it honestly

The reported performance of birthday email is inflated by selection. The people with a birthday on file are people who filled in an optional field, which means they were more engaged than average before the flow existed.

The comparison that means something is against what those same subscribers do in response to your other sends, not against the list average. Run that before concluding the flow is a success — quite often it is performing at about the level that group performs at generally.

Which is not a reason to remove it. It is a reason not to add a form field for it, and to prefer the anniversary that costs nothing.