Cost per acquired customer: the lead math

Most reps compare lead sources by price per lead. That's the wrong number. A $10 lead and a $90 lead can have the exact same true cost — or the cheap one can cost you far more — once you account for how many actually close. The number that matters is cost per acquired customer.

The formula

Cost per acquired customer (CPA) is simple: total spend divided by customers won. Not leads bought — customers won. Price per lead ignores close rate, which is the entire game.

A worked example

Say you spend $900 a month either way. Source A is cheap shared leads at $10 each, so $900 buys 90 of them — but they close at about 2%, for roughly 2 customers. Source B is pricier exclusive leads at $90 each, so $900 buys 10 — but they close at about 12%, because you're not racing nine other reps, for roughly 1.2 customers.

Cost per customer, this example: Source A ≈ $450, Source B ≈ $750. The cheap source looks better — until you add the other half of the math: what a customer is worth. Illustrative figures, to show the shape of the math.

Add lifetime value and the picture flips

If exclusive leads bring better-fit customers — a merchant who stays for years of residual, an account that renews annually — the higher CPA buys a more valuable customer. In the example above, if Source B's customers are worth ~$1,800 in lifetime value versus ~$1,200 for Source A, the "expensive" source is the better buy. The right comparison is CPA against lifetime value, not lead price against lead price.

Track close rate by source, not just cost.
Estimate lifetime value: residual over the account's life, or annual premium times years retained.
Judge a source on profit per customer, not price per lead.

Common questions

What is cost per acquired customer? Total lead spend divided by the number of customers actually won — not leads bought. It accounts for close rate, which price-per-lead ignores.

Why is cost per lead misleading? Because it hides how many leads close. A cheap lead that rarely converts can cost more per signed customer than an expensive lead that closes well.

How do I factor in lifetime value? Estimate what a customer is worth over time — residual income or renewing premium — and compare it to your cost per acquired customer. A higher acquisition cost can still be a bargain if the customer is worth more.

The takeaway

Judge a lead source on cost per signed customer against lifetime value — close rate and fit usually matter more than price per lead. It's the same logic behind how we priced MorningSheet: on the value of a signed account, not on a per-lead sticker. Run your own numbers and the cheapest leads often turn out to be the most expensive.