Customer Acquisition Cost
The total cost of acquiring a new paying customer, including all sales and marketing expenses divided by new customers acquired.
Customer Acquisition Cost (CAC) is the average total cost of acquiring a new paying customer, calculated by dividing all sales and marketing expenses in a period by the number of new customers acquired in that same period (or a lagged version to account for the typical sales cycle length).
CAC = Total Sales & Marketing Expenses ÷ Number of New Customers Acquired
For a company spending $500,000 per month on sales and marketing and acquiring 50 new customers, CAC is $10,000. This simple metric, however, requires careful attention to definitional choices: does 'sales and marketing expenses' include allocated overhead? Salaries? Tools? Event costs? Consistency in definition is essential for meaningful trend analysis.
CAC is meaningless in isolation — its significance only emerges in relation to LTV (Customer Lifetime Value). The LTV/CAC ratio is the core test of unit economics viability. CAC Payback Period (how many months of gross profit to recover the acquisition cost) is often more operationally useful: CAC Payback = CAC ÷ (ARPA × Gross Margin %).
Blended CAC (total new customers including organic/free channels) and paid CAC (new customers from paid channels only) tell different stories. Many companies have a low blended CAC driven by word-of-mouth or SEO, but a very high paid CAC when inorganic channels are isolated. Investors increasingly want to understand the marginal cost of acquiring the next customer, not the average.
CAC varies enormously by company type: PLG (product-led growth) companies may have CAC of $100–$500 for SMB customers, while enterprise SaaS companies targeting Fortune 500 accounts may have CAC of $50,000–$500,000.
FAQs
What is CAC payback period and what benchmark should I target?
CAC payback is the number of months to recover acquisition cost from gross profit. Under 12 months is excellent for SMB SaaS. 12–18 months is acceptable. 18–24 months is typical for mid-market SaaS. Over 24 months is common in enterprise but requires longer-term funding. VCs generally prefer under 18 months.
How do you reduce CAC without cutting growth?
Invest in organic channels (SEO, content, community, word-of-mouth) that have near-zero marginal cost. Improve conversion rates at each funnel stage. Implement product-led growth (free trials, freemium) to let the product sell itself. Shorten sales cycles through better qualification. Improve onboarding to reduce time-to-value.
Should I include customer success costs in CAC?
The prevailing convention is to exclude customer success costs from CAC (since CS retains existing customers, not acquires new ones) and include them in the cost of revenue or 'cost to serve' used to calculate LTV. However, for upsell-driven growth, some CS costs may legitimately be included in expansion CAC.
Related Terms
Customer Lifetime Value
The total net revenue a business expects to earn from a customer over the entire duration of their relationship.
Annual Recurring Revenue
The annualized value of all active recurring subscription contracts, the primary revenue metric for SaaS businesses.
Magic Number
A SaaS sales efficiency metric measuring how much new ARR is generated for every dollar spent on sales and marketing.
Churn Rate
The percentage of customers or revenue lost within a given period due to cancellations or non-renewals.
