Glossary

What is customer acquisition cost (CAC)?

Customer acquisition cost, or CAC, is the total spent on sales and marketing in a period divided by the number of new customers won in that period. It tells you what a new customer costs to win. Compare it with what a customer is worth over time, the customer lifetime value, to see whether growth pays.

Published by Sellinger AI. Numbers and settings checked on 24 October 2026 against the fact register. Report an error.

How do you calculate it?

CAC = sales and marketing cost for the period / new customers won in the period. An example with made up numbers: 30,000 spent in a quarter on salaries, tools and ads, and 15 new customers, gives a CAC of 2,000.

Include: sales and marketing salaries, commissions, tools, data, ads, agencies and events.
Usually exclude: product, support and general overhead.
Be consistent: the same rules every period, so the trend means something.

What is a good CAC?

One that the customer pays back in a reasonable time. Many software companies compare CAC with customer lifetime value and with the months it takes for a customer's margin to repay CAC. There is no universal number; it depends on your prices and margins.

How does outbound affect CAC?

Outbound adds cost per customer through people, tools and data, and lowers it when it wins customers that inbound alone would not. An AI agent changes the mix: less time per conversation, more conversations per person. Measure cost per meeting held and cost per customer, not cost per message sent.

How Sellinger handles it

Sellinger's analytics count people, not messages: the funnel runs Reached, Replied, Meetings and Deals, with show rate, meetings held, no shows and deals won, and a breakdown by ICP, channel, campaign or source. Cost per meeting held is shown; cost per meeting booked is deliberately not. Prices are public: Live Chat from $19, Email from $39, WhatsApp and Instagram from $29, LinkedIn $198 per agent, bundles $249 to $1,199.

Common questions

Should founders' time count in CAC?

If founders sell, a fair share of their time belongs in it, or CAC will look too low.

What is blended CAC?

CAC across all channels together. Channel CAC splits it by source, which is more useful for decisions.

How do I lower CAC?

Win more of the right customers per unit of spend: better lists, faster replies and fewer lost meetings.

Sources and method

Formula and example are illustrative. Sellinger prices and analytics from the fact register and the analytics help article, checked 24 October 2026.