Which metric is most directly used to assess cost efficiency per customer acquisition?

• A. CPC
• B. ROI
• C. CPA
• D. Impressions

Answer: (C)

Measuring cost efficiency per customer acquisition comes down to how much you spend to bring in each new customer. The most direct metric for this is CPA, which stands for cost per acquisition and is calculated as total advertising spend divided by the number of conversions (customers acquired). This metric directly ties spend to the actual outcome of acquiring customers, so it shows how efficiently your ad spend is turning into new customers.

Cost per click gives the price of each click, not whether those clicks convert into customers. ROI looks at overall profitability relative to cost, which is broader than just the cost to acquire a customer. Impressions count how often ads are shown, not how much was spent per acquisition or how many customers were gained. Therefore, CPA best measures cost efficiency per customer acquisition.