Predictive LTV forecasts customer lifetime value using machine learning models. Differs from historic LTV by projecting future revenue instead of measuring past spend.

CAC payback period measures months to recover customer acquisition cost from gross margin. Essential cash flow metric for growth teams.

Marketing Efficiency Ratio (MER) measures revenue generated per dollar spent on ads. Essential metric for DTC profitability.

Media mix modeling quantifies channel contribution to revenue when attribution breaks down. When to use MMM over MTA for ecommerce.

Involuntary churn occurs when customers lose access due to payment failure, not cancellation. Typically 20-40% of total churn; recoverable via retry logic.