LTGP : CAC
Lifetime gross profit ÷ customer acquisition cost. If this is right, everything else is solvable. Target: ≥3x minimum, ≥5x to scale.
How it's calculated
LTGP= sum of ticket value from every enrollment by customers acquired in that month (across all time, not just the month they joined) minus the month's direct costs (tutor pay, materials, software per seat). Direct costs are operator-entered per row until Amex + Gusto auto-pull is wired.
CAC= total ad spend that month ÷ new customers acquired that month. Setter pay and operator time aren't in the spend number yet — when they are, CAC goes up and the ratio drops.
Lifetime is genuinely lifetime — if a customer enrolls a sibling next year, that revenue rolls into their original acquisition month. So this metric appreciates over time as customers come back.