Cost per Acquisition (CPA) is a critical performance marketing metric that measures the aggregate cost to acquire one paying customer. It is calculated by dividing the total cost of a campaign (or all marketing efforts) by the number of customers acquired from that campaign: Total Campaign Cost \/ Number of Customers Acquired. Unlike metrics like clicks or impressions, CPA is directly tied to a bottom-line business outcome\u2014a sale. It is the ultimate measure of marketing efficiency. A low CPA indicates that a company is acquiring customers cheaply and efficiently, while a high CPA can signal an unsustainable business model, especially if the customer lifetime value (LTV) is not significantly higher. Marketers use CPA to evaluate the profitability of specific channels, campaigns, and keywords. It is a key lever in bidding strategies for platforms like Google Ads, where advertisers can set a target CPA, and the algorithm automatically adjusts bids to try and acquire customers at or below that cost. Managing and optimizing for a target CPA is essential for scaling an e-commerce business profitably, as it ensures that marketing spend is directly correlated with revenue growth.<\/p>\n\n\n\n