What is Customer Acquisition Cost (CAC)?

How CAC is calculated: sum all sales and marketing expenses for a defined period and divide by the number of new customers acquired in that period. Expenses should include paid media, content/creative tied to acquisition, lead-gen tools, third-party data/enrichment costs, salaries and commissions attributable to new-logo activity, and onboarding costs directly required to convert a customer.

Where it fits: CAC sits at the center of unit economics. Calculate at company, product-line, channel, and cohort levels. For channels, attribute only the expenses and customers that can be reasonably traced to that channel. For cohorts, calculate CAC for customers acquired in the same timeframe to measure acquisition effectiveness and cohort-specific ROI.

CAC directly impacts growth velocity and capital efficiency. High CAC can erode margins and delay payback, forcing companies to raise more capital or slow growth. Lowering CAC increases ROI on marketing and sales investments, shortens payback period, and improves LTV:CAC ratios—critical inputs for forecasting ARR and making hiring and channel-allocation decisions.

Operationally, CAC informs budget allocation, compensations for revenue teams, and prioritization of channels and campaigns. For revenue operations, tracking CAC by cohort and channel uncovers which tactics scale profitably and where to apply enrichment, process changes, or automation to reduce acquisition unit cost.

Acme SaaS closed 40 new customers in Q2. Their acquisition expenses for the quarter were $120,000 in paid media, $30,000 in content and events, $50,000 in sales and SDR salaries apportioned to new-logo activity, and $10,000 in onboarding. Total acquisition spend = $210,000; CAC = $210,000 / 40 = $5,250. Leadership uses this to compare channel CAC, prioritize high-performing campaigns, and model payback against LTV.