A never-tested close rate builds a business that works on paper

The symptom

A revenue-per-buyer figure looks healthy enough to justify an acquisition budget, and actual sales never quite reach the rate the model assumed.

The cause

A buyer-to-customer rate is two numbers multiplied together: the share of buyers who'll take a conversation when you reach out, and the share of those conversations that actually close. Using a hopeful projection for either number, rather than history, conveniently justifies whatever spend was already planned. The model survives a bad guess on the ask rate and dies on a bad guess on the close rate, which is exactly the number most likely to be guessed rather than measured.

The fix

Pull both rates from your actual last twenty customers, not a hopeful estimate. Close the ledger monthly rather than pooling your whole history into one average; a price or offer change starts a new era, and blending two eras describes no real buyer you've actually met. Mark every estimated cell provisional with a date to replace it. Then stress it: halve the close rate and re-run the whole sum, because that's the input the model is most sensitive to.

How to spot it

Ask where your current close rate figure came from. If the answer is an estimate, a target, or an old number from before a pricing or offer change, rebuild it from your actual last twenty customers and re-run your acquisition math against the new figure before trusting any budget decision built on the old one.