A bad day
A holiday, a payment outage or a tracking incident hit every user at once.
Every daily total mixes users acquired today, last week and months ago. Tell Me Why decomposes each day’s result by cohort age, so you can tell a calendar event from a change in the quality of the users you are buying.
A single line on a chart cannot say which one is true. Each story calls for a different action.
A holiday, a payment outage or a tracking incident hit every user at once.
Acquisition volume fell, so there was less first-day revenue to count.
Volume held, but recently acquired users monetize less than before.
Mature users are spending less, while new ones behave as usual.
Rows are calendar days. Columns are the age of the users generating the result, in days since acquisition. Each cell is the contribution of users of that age on that date, and every row adds up to the daily total you already know.
| Date ↓ · Age → | D0 | D1 | D2 | D3 | D4–7 | D8+ | Total |
|---|---|---|---|---|---|---|---|
| Mon 14 | 1.9k | 0.9k | 0.6k | 0.5k | 0.8k | 0.9k | 5.6k |
| Tue 15 | 2.0k | 0.9k | 0.6k | 0.5k | 0.8k | 0.9k | 5.7k |
| Wed 16 | 0.7k | 0.4k | 0.3k | 0.2k | 0.3k | 0.4k | 2.3k |
| Thu 17 | 1.8k | 0.9k | 0.6k | 0.5k | 0.8k | 0.9k | 5.5k |
| Fri 18 | 2.2k | 1.0k | 0.6k | 0.5k | 0.8k | 0.9k | 6.0k |
Because a cohort acquired on a given day moves one column to the right every day it ages, the direction of a pattern in the grid points straight to its cause.
Every age moves together on the same date. Think holidays, outages, tracking gaps or a platform-wide change. Fix the incident; don’t cut the traffic.
The same group of users stands out day after day as it ages. A specific campaign, source or creative brought in stronger or weaker users.
From one day onward, users of the same age behave differently, for example all new users on their first day. Look at onboarding, pricing or offer changes released that day.
Stack each day’s result by cohort age and the story behind the curve appears. A one-day dip that hits every layer is a calendar event. A thinning base layer that persists means new cohorts are monetizing less, even while the total still looks acceptable.
Counts, revenue, ARPU, LTV or ROI, built on the acquisition and revenue events you defined.
Select the calendar range around the change you want to explain.
Row, diagonal or column: the pattern in the grid points to the cause.
Keep the configuration and reopen it whenever the same question comes back.
Check whether the drop is concentrated on specific dates or spread across the youngest users before touching budgets.
Scaling can bring in lower-value users. Watch whether the youngest ages keep their contribution as volume grows.
A gap that hits every age on the same day points to collection, not to customers. Verify events before drawing conclusions.
Compare the same ages before and after the release date to see who reacted, and how.
Views finds the segment, Cohort shows how it matures, the ARPU forecast estimates what it will be worth. Tell Me Why explains why a number moved.
See every daily result split by cohort age, and act on the real cause.