Term
CPA (Cost per Acquisition)
Advertising KPI: average cost per conversion. Central efficiency metric for lead gen and performance marketing, and the steering input for tCPA bidding.
CPA (Cost per Acquisition) — in more detail
CPA stands for “Cost per Acquisition” (sometimes “Cost per Action”) — the average cost required to deliver one conversion. Formula: total cost ÷ conversions. What counts as “acquisition” is defined by the conversion action: lead, purchase, app install, phone call. In e-commerce, ROAS usually carries more signal (because order values vary widely); in lead gen, CPA is the central steering metric. tCPA (Target CPA) is the Smart Bidding strategy that allocates clicks so the average CPA hits the target value.
Example / In practice
A B2B demo lead-gen campaign reports €12,000 spend and 80 demo requests → CPA €150. If the average demo-to-deal conversion rate is 20 % and the average deal value €5,000, a CPA of €150 is highly profitable — the absolute number is only meaningful relative to business value.
Distinction from similar terms
CPL (Cost per Lead) is the CPA special case where the conversion is a lead. CPO (Cost per Order) is the e-commerce variant. ROAS and POAS factor in revenue or margin. tCPA is the matching bidding strategy.
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ROAS (Return on Ad Spend)
Advertising KPI: ratio of conversion revenue to ad spend. Central steering metric in e-commerce and the input for tROAS bidding.
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