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What Is Customer Acquisition Cost (CAC)?
Analytics & Data
Updated 18 September 2026
Quick Answer
Customer Acquisition Cost (CAC) is the total cost of gaining one new customer, including all marketing and sales expenses — closely related to CPA, and used to judge whether growth spending is sustainable.
CAC vs. Cost Per Acquisition (CPA) — What's the Difference?
| CAC | Cost Per Acquisition (CPA) | |
|---|---|---|
| Scope | Often includes broader sales and marketing costs | Typically focused specifically on marketing/ad spend |
Why It Matters
- Comparing CAC against Customer Lifetime Value reveals whether your growth is actually sustainable, not just producing customers at any cost.
- A rising CAC over time can be an early warning sign of increasing competition or declining marketing efficiency.
How It Works
- Total marketing and sales costs over a period are tracked.
- The number of new customers gained in that period is counted.
- CAC = Total Marketing & Sales Cost ÷ Number of New Customers.
Key Takeaways
- CAC is the total cost of gaining one new customer, including sales and marketing.
- It should be compared against Customer Lifetime Value to judge sustainability.
- A rising CAC over time is a signal worth investigating.
Frequently Asked Questions
What's a healthy CAC?
It should be meaningfully lower than your Customer Lifetime Value — a common rule of thumb is CLV being at least three times CAC, though this varies by business.
How is CAC different from CPA?
They're closely related; CAC sometimes includes broader sales costs beyond just marketing spend, though usage varies.
Why would CAC increase over time?
Increased competition, market saturation, or declining marketing efficiency are all common causes.