What Is Customer Acquisition Cost (CAC)?
Customer acquisition cost (CAC) is the average amount a business spends on sales and marketing to gain one new paying customer. It includes ad spend and usually other acquisition costs, such as agency fees, marketing software, sales salaries and commissions, depending on how the business defines it.
CAC is related to cost per acquisition (CPA), but they are not identical. CPA often measures the cost of a specific action within a channel, like a lead or a form fill. CAC measures the full cost of turning someone into an actual paying customer.
Why Customer Acquisition Cost Matters
Growth only creates value if customers are worth more than they cost to win. CAC tells you what that cost is, so you can judge whether your marketing is profitable and how much you can afford to scale.
- It reveals whether marketing spend is turning into customers efficiently.
- It helps compare channels on true customer outcomes, not just clicks or leads.
- Paired with lifetime value (LTV), it shows whether growth is sustainable.
- It sets clear spending limits for campaigns and new channels.
How to Calculate Customer Acquisition Cost
CAC = Total sales and marketing costs in a period / Number of new customers acquired in that period
For example, if a repair shop spends $6,000 in a month on ads, agency fees and marketing tools and gains 75 new customers, its CAC is $80.
Two related measures are useful:
- LTV:CAC ratio: Lifetime value divided by CAC. Many subscription businesses aim for a ratio of roughly 3:1 or better, though the right target varies by industry and margins.
- CAC payback period: How many months of gross profit it takes to recover CAC.
Be consistent about what you include. “Paid CAC” using only ad spend will look much lower than “fully loaded CAC” that includes salaries and tools.
Customer Acquisition Cost in Automotive Marketing
Automotive businesses often measure related versions of CAC, such as cost per sale or cost per new repair order.
- Dealerships: Cost per vehicle sold divides advertising and lead costs by units sold. Breaking it down by channel, such as paid search, social, third-party leads and organic, shows which sources produce sales efficiently. Because a service customer may return for years, the true value of a buyer can extend well beyond the sale.
- Collision shops: Cost per new customer from direct-to-consumer marketing can be compared with the value of the average repair and the cost of other referral sources.
- Repair and tire shops: A first visit may be a discounted oil change, so CAC must be judged against repeat visits over time, not the first ticket.
- Parts ecommerce: CAC compared against first-order margin and repeat purchase rate tells a brand how aggressively it can spend.
- Automotive SaaS: CAC compared against ARR per customer and payback period guides sales and marketing investment.
What Is a Good Customer Acquisition Cost?
There is no universal good CAC; it depends on margins, purchase value and how long customers stay. A CAC that would be ruinous for a car wash membership could be very profitable for a vehicle sale or a multi-year software contract. Judge CAC against customer value.
- Track CAC by channel and campaign, not just as one blended number.
- Connect marketing data to your CRM, DMS or ecommerce platform so you count real customers, not leads.
- Compare CAC with lifetime value and payback period before scaling spend.
- Lower CAC by improving conversion rates, lead handling and follow-up, not only by cutting ad costs.
- Invest in retention and referrals, which reduce the need for paid acquisition.
- Recalculate regularly, as CAC rises when competitors bid up the same audiences.