The fundamentals don’t fail in a crisis. They drift, one missed check at a time. A fixed weekly, monthly and quarterly rhythm is what stops the drift.
Every number in this book is easy to check once. The discipline is checking them every week, in the same order, whether or not anything seems wrong. The weeks when nothing seems wrong are when the welcome series quietly breaks.
| Line | Number | From |
|---|---|---|
| 1 | New customers, new-customer cost, first-order contribution, second-order rate for the cohort from 90 days ago | Chapter 3 |
| 2 | MER and new-customer MER, with the four-week trend | Chapter 3 |
| 3 | Share of revenue from returning customers | Chapter 3 |
| 4 | Engaged subscribers, and net change this week | Chapter 12 |
| 5 | Spam complaint rate, from Postmaster Tools | Chapter 13 |
| 6 | Revenue per recipient for welcome, cart and post-purchase | Chapter 14 |
| 7 | Tests live, and any that finished, with the lesson | Chapter 21 |
Seven lines. If a line moved more than you’d expect, it gets one sentence of explanation and one owner. If nothing moved, the meeting takes ten minutes. That’s the point.
The weeks when nothing seems wrong are when things quietly break.
Once a month, a longer report answers four questions in this order. What happened to the four numbers, and why. What the cohort table says about customers won in the last three months compared with the same months last year. How the owned channels did against the health thresholds in chapter 18. What the tests taught, and what’s next. Keep it to a few pages. A report nobody reads is worse than none, because it lets everyone believe someone is watching.
Keep a dated log of every change to the machine: a new offer, a flow edited, a popup changed, a budget moved, a price raised. One line each. When a number moves three weeks from now, the changelog is how you find out why in five minutes instead of arguing about it for an afternoon. From my work, it’s the single cheapest habit that separates teams who learn from teams who guess.
Once a quarter, re-score The Machine Audit. The scores stay in your browser from last time. Compare. Any check that went down gets an owner and a date. Any check that’s been at 2 for a year might be ready for a harder test: a holdout on a flow, a geo test on a channel, a price test on an offer.
This is one chapter of The Whole Machine, which is free and readable in full on a single page with no form in front of it.