11 December 2025 · Isolde Venn
Reading a retention curve without the folklore
Folklore says a healthy consumer product retains on day seven. Folklore is how a mortgage tracker and a casual game end up sharing a slide. Retention Isolines, the shorter survey in our catalogue, exists because App Analytics borrowed a window from social apps and never gave it back.
A curve is a set of heights at chosen distances from first use. Those distances must be distances the product actually travels. If sellers restock on a fortnight, D7 is a trench you dug for the picture. If guests book travel twice a year, D30 is still a rumour. Print the isolines that match the field, and write the limitation in the same paragraph as the number.
The Midlands marketplace in our readings looked like a cliff until the window moved to fourteen days aligned to first list. Nothing about the product had “improved.” The folklore had been removed. That is the opposite of the story a growth lead sometimes wants, and it is the only story the house will mark in week six.
If you take one practice from Ponts Green: never present a retention percentage without naming the return event, the window, and the identity seam. Missing any of the three, the curve is decoration. Decoration is allowed on a wall. It is not allowed in a board pack that claims to be App Analytics.