Completion rate: what it is and how to calculate it

It is worth measuring because it says whether the thing you wrote is being used, and because it is the one funnel figure that cannot be improved by putting more strangers on a list. A course with a high sign-up rate and a low completion rate is a promise that was better than the material behind it.

To calculate it, divide the readers who reached the last day by the readers who confirmed. If 200 people confirmed and 46 of them pressed the link in day five, the completion rate is 46 divided by 200, which is 0.23, or a little under one reader in four. Count from confirmed readers rather than from everyone who filled in the form, because an address that never confirmed was never sent day one and had nothing to finish.

Three different figures get called a completion rate, so say which one you mean whenever you quote it. The share of readers who were sent every day only says that nobody unsubscribed or bounced on the way. The share who opened the last day is inflated by mail software that fetches images on its own. The share who did something on the last day, a click or a reply, is the one that describes a person, and it is the lowest of the three.

Measure it with a click rather than an open, and give every day one link a reader who did the work has a reason to press. Published benchmarks disagree by wide margins here, because completion moves more with who the reader is and what was promised than with anything you can edit in the copy.

Most of what moves it is decided before day one goes out: how specific the promise on the sign-up page was, how many days there are, and whether each day can be done in the time a reader has that morning. A shorter course loses fewer readers on the way, so a first course is safer at five days than at ten, and the day where the figure drops is the day to rewrite.