Cost Per Acquisition (CPA)
The cost of acquiring one converting customer through a specific marketing channel or campaign.
Definition
CPA measures the cost of a single conversion through a specific channel or campaign. While CAC is a blended company-wide metric, CPA is channel-specific: "Our Google Ads CPA is $45, while our content marketing CPA is $22." CPA helps you allocate marketing budget to the most efficient channels.
CPA can also refer to non-purchase conversions: cost per lead, cost per trial signup, cost per app install. The key is clearly defining what "acquisition" means for each context.
Why it matters for founders
CPA tells you which channels are efficient and which are burning money. By comparing CPA across channels to the revenue each channel's customers generate, you can optimize your marketing mix for maximum ROI.
Example
A DTC brand tracks CPA across channels: Facebook Ads ($35), Google Search ($28), Instagram Influencers ($52), Email Marketing ($8). Despite higher volume from Facebook, they shift budget to Google and Email where CPA is lowest relative to LTV.
How Foundra helps
Foundra's Outreach Script + Plan card helps you test acquisition channels at low cost before committing budget, so you know your CPA before scaling spend.
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Related terms
Customer Acquisition Cost (CAC)
The total cost to acquire one new customer.
Return on Ad Spend (ROAS)
The revenue generated for every dollar spent on advertising.
Lifetime Value (LTV)
The total revenue a customer generates over their entire relationship with your business.
Unit Economics
The revenue and costs associated with a single unit of your business (usually one customer).