Agency Echelon
Reference

CPA is media cost per conversion; CAC is total sales and marketing cost per new customer. CPA counts every conversion, including repeat buyers and leads that never close, and includes only media. CAC counts only new customers and includes salaries, tools, creative, and agency fees. A $40 CPA can be a $150 CAC once conversions are filtered to new customers and the full cost is loaded.

CPACAC
NumeratorMedia spendAll sales and marketing cost
DenominatorConversionsNew customers
ScopeCampaign or channelBusiness or channel
Used byMedia teamsFinance and leadership
Compared toConversion valueLifetime value

Terms in this comparison

Cite this page: Agency Echelon. "CPA vs CAC." Agency Echelon Reference, reviewed September 2026. https://agencyechelon.com/reference/compare/cpa-vs-cac/

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Reviewed September 23, 2026. Reference text is licensed CC BY 4.0. Privacy