Customer Acquisition Cost (CAC) is fully loaded sales and marketing spend divided by the number of new customers acquired in the same period.
Customer Acquisition Cost (CAC) is fully loaded sales and marketing spend divided by the number of new customers acquired in the same period. It answers a single question: how much did we spend to land that customer?
The math is straightforward. Add all sales salaries, commissions, marketing spend, tools, and overhead for a quarter or year, then divide by the net new customers you closed in that same period. If you spent $400,000 on sales and marketing and landed 50 new customers, your CAC is $8,000.
CAC shows up in discovery when a prospect asks: "How will this pay for itself?" If your deal value is $5,000 and your CAC is $8,000, you're underwater on that customer until year two. Knowing your CAC lets you talk about ROI timeline with authority instead of guessing.
Enterprise deals move CAC up. A company spending $50,000 annually can absorb a higher CAC than a $5,000 customer. This is why expansion revenue—adding seats or tier upgrades to existing customers—has 3–5x better CAC efficiency than new logo acquisition. You don't spend another $8,000 to land a $10,000 upgrade with someone already in your system.
| Term | Definition | What it tells you |
|---|---|---|
| CAC | Sales + marketing cost per new customer | How expensive it is to acquire |
| LTV (Lifetime Value) | Total revenue a customer generates over their entire relationship | How profitable they become |
| LTV:CAC ratio | LTV divided by CAC | Whether acquisition economics work at scale |
| CAC payback | Months until revenue from a customer covers acquisition cost | How fast you recover the investment |
Healthy B2B SaaS targets a CAC payback under 12 months and an LTV:CAC ratio above 3:1. If your LTV:CAC is 2:1, you're paying too much to acquire, or customers aren't staying long enough. If it's 5:1, you have room to spend more on sales and marketing without breaking unit economics.
Sales teams conflate CAC with "what this deal cost us to close." A rep says, "This customer cost us $15,000 to land because we had a 6-month sales cycle and three people touched the deal." That's not CAC—that's deal-specific cost. CAC is your average cost across all deals in a period. One $15,000 deal and one $2,000 deal average to $8,500.
This matters because it tells you whether to be aggressive or selective. If your CAC is $8,000 and a prospect is a poor fit for year one, walking away saves money. If it's $2,000 and you close everything that breathes, you're leaving payback on the table.
CAC surfaces naturally when a buyer is concerned about implementation cost, time to value, or ROI. "Our payback period is 8 months because the average customer generates $50,000 in year-one value" sets expectation and shows you've done the math. It also lets you talk honestly about which customers are good fits. A customer with $5,000 ARR isn't viable at your CAC, and saying so early saves everyone time.
Sum all compensation, commissions, and tools across every team involved in acquisition—sales, marketing, SDRs, and management. Divide the total by new customers closed in that same period. It's messier with shared teams, but allocate based on what percentage of time each person spends on new customer acquisition versus retention.
No. CAC covers only acquisition—sales and marketing spend to get them to contract. Customer success (onboarding, support, renewals) is part of the total cost to serve, but not CAC. Mixing them makes it harder to optimize each separately.
Over 12 months is a red flag in most B2B SaaS. If it takes 18 months to recover acquisition cost, cash flow tightens and scaling becomes expensive. Payback under 12 months means your sales engine funds itself faster and lets you reinvest sooner.
It doesn't—CAC divides total spend by customers acquired, not by sales cycle length. A long sales cycle uses up more calendar time and seller capacity, which affects your quota attainment and hiring needs, but the CAC number itself stays the same if spend is consistent.
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