Cost per acquisition (CPA)
In short
Cost per acquisition (CPA) is the amount spent to earn one specific conversion. The formula is total cost divided by the number of conversions. The conversion can be a paying customer, a trial signup, or a booked demo, so always state what counts.
CPA is often used for ad campaigns. Customer acquisition cost (CAC) is the broader, fully loaded version that includes sales and marketing salaries and tools.
How to calculate CPA
Say a team spends 10,000 on a paid campaign and gets 50 trial signups. CPA is 200 per signup. If 10 of them become customers, the cost per customer acquired is 1,000. Both numbers are useful, but they answer different questions.
Where CPA fits
- CPA vs CAC: CPA usually covers one campaign or channel. CAC covers all sales and marketing cost for new customers.
- CPA vs cost per lead: Cost per lead counts any lead. CPA counts a later, more valuable action.
- CPA vs CPM: CPM is the price for 1,000 impressions. CPA is the price for a conversion.
How to lower CPA
- Tighten targeting: Focus spend on accounts that match your ICP.
- Improve the landing page: A higher conversion rate lowers CPA without changing spend.
- Match message to audience: Relevant ads and offers raise conversion rates.
- Cut weak channels: Move budget from high-CPA sources to ones that convert.
- Follow up faster: Quick response turns more leads into conversions.
Common mistakes
- Optimizing for the cheapest conversion: A low CPA for low-quality signups can raise cost per real customer.
- Ignoring lifetime value: A higher CPA can be fine if customers stay and expand. Compare it with the value of each customer.
- Mixing definitions: Compare CPA only when the conversion type is the same.
- Short windows: B2B cycles are long, so wait for conversions to mature.
Cost per acquisition FAQs
What is cost per acquisition (CPA)?
Cost per acquisition is the average cost to obtain one defined conversion, such as a customer, trial, or sale. You calculate it by dividing the total campaign cost by the number of conversions it produced.
How do you calculate cost per acquisition?
Divide total spend by the number of conversions. For example, 10,000 spent on a campaign that produces 50 conversions gives a CPA of 200. Make sure the conversion definition is the same across the campaigns you compare.
What is the difference between CPA and CAC?
CPA usually measures the cost of a conversion in one campaign or channel. CAC includes all sales and marketing costs, such as salaries and tools, spent to win a new customer, so it is broader and usually higher.
What is a good cost per acquisition?
It depends on what each customer is worth. A CPA is healthy when it is well below the gross profit that customer generates over their lifetime, and when you can pay it back within an acceptable period for your business.
