CAC (Customer Acquisition Cost) is the average cost to acquire one new customer. Calculate it by dividing total marketing and sales spend over a period by the number of new customers gained in the same period. It is a core metric for judging marketing efficiency and business sustainability.
Formula and Included Items
CAC = Total marketing and sales spend ÷ New customers
Total spend is not just ad spend. Include the following items for accuracy:
- Media ad spend (CPC, CPM based campaigns)
- Marketing and sales labor costs
- Content production and outsourcing costs
- Subscription fees for tools and solutions in use
Calculating with ad spend alone makes CAC look lower than it is. Breaking it out by channel reveals where waste occurs.
Why It Matters
If CAC exceeds the lifetime value a customer brings (LTV), you lose money on every sale. That is why you also track the LTV ÷ CAC ratio.
| LTV/CAC | Interpretation |
|---|---|
| Below 1 | Loss-making structure, fix immediately |
| 1-3 | Limited growth headroom |
| 3 or above | Healthy unit economics |
| Above 5 | Underinvestment, possible missed growth |
CAC pairs with ROAS and ROI. Check short-term efficiency with ROAS and long-term profitability with LTV/CAC.
How to Lower CAC
- Improve conversion rate: more customers from the same traffic
- Optimize landing pages to cut bounce rate
- Increase the share of compounding asset-type channels
SEO and content SEO in particular keep driving traffic without ad spend once they build up. Channel cost per acquisition falls over time.
Recently, GEO has also emerged as a new acquisition path. Being cited in AI answers generates exposure without ad bidding. 238lab combines SEO and GEO to reduce dependence on paid channels and structurally lower CAC.
Notes
- CAC is only meaningful when analyzed by channel and time period.
- Standardize your definition of a new customer first (signup, payment, exclude repeat purchases).
- Paid channels see frequent cost increases, so balance them with asset-type channels.