The unit economics spreadsheet nobody opened
It lived on page four of a Notion doc, was updated quarterly, and was wrong by sixty percent. Nobody noticed until the term sheet.
A founder I worked with had a CAC of $1,200 and an LTV of $8,400 on the unit economics page of his pitch deck. The numbers had been there for eighteen months. They were both wrong. CAC, fully loaded, was closer to $2,100. LTV, after honest churn, was closer to $5,300. The LTV-to-CAC ratio he had been quoting was 7.0. The ratio he actually had was 2.5.
He learned this the way founders almost always learn it. A sophisticated investor recomputed the numbers in front of him during diligence, on a Zoom, with a shared screen. The recomputation took fourteen minutes. The implications took the rest of the round to recover from.
Unit economics is the only metric in a company whose drift is invisible until it is catastrophic. ARR is on a dashboard. Burn is on a dashboard. Pipeline is on a dashboard. CAC and LTV almost never are, because they require a small monthly act of accounting discipline that nobody owns by default. The numbers, left alone, drift in the wrong direction with the same reliability as a refrigerator with the door cracked open. The drift is silent. By the time the room is warm, the food is already bad.
The two errors are predictable. CAC tends to be reported lean — sales salaries excluded, marketing tooling excluded, the contractor who runs paid acquisition somehow not appearing. The number gets the friendliest possible denominator: the customers who closed because of marketing, rather than every customer who closed. LTV tends to be reported generous — contribution margin gross, not net of customer success cost, and churn averaged over the wrong cohort. Both errors push the ratio in the flattering direction. Both happen by default, without anyone deciding to lie.
The fix is small enough to be embarrassing. One number. One named owner — usually the head of finance, sometimes the founder. One monthly review of thirty minutes, with a single source-of-truth document that updates the inputs from the same underlying systems every time. The review catches drift within one quarter. The quarterly version catches it within four — too late if you happen to be raising in months two through eleven.
Founders who can recite their current CAC and LTV from memory raise faster than founders who have to look them up. This is not because investors test it explicitly. It is because the recitation reveals which founder has been running the company on the actual numbers and which one has been running it on the deck. The first kind raises. The second kind explains.
The unit economics page in your deck is a claim. The spreadsheet behind it is the evidence. If you have not opened the spreadsheet this month, the claim is almost certainly false in the direction that hurts you the most. The next term sheet is the audit you didn't run on yourself. Run it earlier.