Field Notes
Customer economics get distorted when cohort logic is weak.
LTV and CAC can look precise while quietly matching the wrong customers, costs, periods, discounts, and retention behavior.
The visible claim
A ratio says one channel, segment, or product is profitable.
The hidden defect
Costs and customers may be matched across the wrong periods. Retention and expansion may be averaged in ways that hide the real economics.
What to check
Check cohort definition, acquisition cost timing, revenue timing, discounts, churn, expansion, and segment mix.
The fix
Build the analysis around customer behavior over time. Do not let one blended ratio carry the decision.