The most important question in advertising isn't "how many people saw it?" but "how much did each customer cost me?"
The formula
Cost per customer = ad spend ÷ number of customers who came in
A simple example
You invested $100 and 35 customers came in (people who messaged with real interest or booked):
$100 ÷ 35 = about $2.86 per customer.
If each customer brings you, say, $40 in profit, that ad is a great deal.
Why this number changes everything
- It tells you if the ad is worth it when you compare it with what you earn per customer.
- It lets you plan: if every $100 brings in about 35 customers, you know how much to invest to hit your goal for the month.
- It tells you when to scale: with a stable cost per customer, a daily budget makes sense.
Messages vs. customers
Be careful not to confuse messages with customers. If 100 messages come in but only 5 buy, your real cost is based on those 5. That's why we measure lead quality, as we explain in How to tell if an ad is working.
The numbers in this example are for illustration. Every business has its own cost per customer; what matters is measuring it.
Want ads that bring in customers, not just expenses?
We test before investing, pause what doesn't work and scale what does.
Frequently asked questions
What's a good cost per customer?
It depends on how much you earn per customer. If the cost per customer is well below your profit per customer, the ad is profitable.
Do you give me these numbers?
Yes. We show you your ad results so you know how much each customer costs you.
