What is CAC (Customer Acquisition Cost)?
CAC is calculated by dividing total marketing and sales cost in a given period by the number of customers acquired in that period. Ad budget, team salaries, tool licences, agency fees and campaign production costs — every direct and indirect line item — belongs in this calculation.
CAC on its own isn't good or bad; it only becomes meaningful next to LTV (Lifetime Value) and CAC payback period. The widely accepted rule is that LTV / CAC of 3x or higher signals healthy unit economics; a ratio below 1 means every new customer loses money for the business.
The best strategies for optimising CAC are channel-level attribution, conversion rate optimisation, shortening the sales cycle and strengthening organic and referral channels. Alignment between marketing and sales is one of the most decisive operational factors.
Worked example: blended CAC, paid CAC and payback
A company spending $5,000 on marketing (of which $3,500 on ads) and $3,000 on sales in a month, winning 100 new customers, has a blended CAC of $80. If 60 of them came from paid ads, paid CAC is $3,500 / 60 ≈ $58. With $15 monthly revenue per customer and a 75% gross margin, each customer contributes $11.25 a month, so CAC pays back in about 7.1 months.
CAC in B2B
Because B2B sales cycles span weeks or months, this month's spend often wins next quarter's customers. Lag spend by your average sales cycle or use a 3-month rolling average, and track cost per lead, per SQL and per customer separately to find the bottleneck.