WHAT YOU WILL PRACTICE
Calculate a simple funnel and separate conversion, retention and acquisition cost.
Use explicit denominators
If 12 of 200 visitors begin a trial, visitor-to-trial conversion is 6%. If three of those trials become customers, trial-to-customer conversion is 25%, while visitor-to-customer conversion is 1.5%. Label the stage and period.
Count the cost of learning
Cash acquisition cost is campaign spend divided by acquired customers. Founder time is not free: estimate it separately and make the hourly assumption visible. With zero customers, cost per customer is undefined, not zero.
Check what happens after signup
A first conversion does not prove ongoing value. Measure a useful activation event and later repeat use within a clear cohort. Avoid mixing this month’s traffic with customers acquired months earlier.
IN PRACTICE · ORIGINAL EXAMPLE
A campaign reaches 200 visitors, produces 12 trials and three customers, with $60 cash spend. Cash cost per customer is $20. Four hours of work valued at $25/hour would add $100, making the fully allocated estimate $53.33 per customer.
Do not call a channel profitable without considering gross margin, delivery costs, retention and the full acquisition effort.