New customers, what each one cost, what their first order left, and how many come back. Almost everything else is a detail of one of these.
A DTC business can be written as one sentence: this many new customers, at this cost each, leaving this much on the first order, with this share coming back. If you can fill in that sentence every Monday, you can run the company. If you can’t, no dashboard will save you.
| Number | How to count it | Why it’s here |
|---|---|---|
| New customers | People whose first-ever order was this week. Not orders, not sessions, not “new visitors”. | It’s the only measure of whether the business is growing its base. |
| New-customer cost | All marketing spend this week divided by new customers this week. | It’s what you pay per unit of growth, with nothing hidden. |
| First-order contribution | Average CM2 on those new customers’ first orders. | It’s what each unit of growth pays back on day one. |
| Second-order rate | Share of a cohort that orders again within 90 days, then 180 and 365. | It’s what turns a costly first order into a profitable customer. |
Notice the second number uses all marketing spend, including brand, retention tooling and agency fees, divided only by new customers. That’s deliberate. It’s the harshest version, and it’s the only one that can’t be gamed by moving spend between labels. Keep the channel-level versions too; just don’t run the business on them.
Fill in one sentence every Monday: how many new customers, at what cost, leaving what, with how many coming back.
Return on ad spend is each platform’s claim about the revenue its ads caused. Every platform counts the same order if it touched the customer, so the platforms’ claims added together often come to more than the business actually sold. The reported number also mixes new and returning customers, so an ad account can post a better ROAS by retargeting people who were going to buy anyway. Chapter 8 covers what those claims are worth.
Two blended ratios fix most of this. Marketing efficiency ratio, or MER, is total revenue divided by total marketing spend. New-customer MER is revenue from first orders divided by total spend. Neither pretends to know which ad did what. Both go up when the whole machine works better, and new-customer MER can’t be propped up by harvesting existing customers.
One more ratio belongs on the page, as context rather than a target: the share of revenue that comes from returning customers. Too low, and the business is renting every order from an ad platform. Too high, and it’s living off a base it has stopped refilling. I look at the trend more than the level. A share that climbs while new customers fall is the classic early warning: the business looks stable because old customers are still buying, and the base is quietly shrinking under it.
The four numbers are most useful when they move in different directions, because each combination points somewhere specific. New customers up and new-customer cost up together is normal scaling; you’re buying further into the audience. New customers down and cost up means the creative or the offer has stopped working, and the fix is in part two or three. First-order contribution down with everything else steady is almost always discounting or product mix: someone added a code, or a cheaper product started winning in the ads. Second-order rate down for a recent cohort is the one to worry about most, because by the time it shows up in revenue, several more cohorts like it have already been bought.
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.