When searching, use specific phrases like "Stephan Sorger textbook PDF chapter 3 metrics" rather than the full title to find legitimate supplementary materials.

| Category | Metric | Formula / Definition | Strategic Value | | :--- | :--- | :--- | :--- | | | Customer Acquisition Cost (CAC) | Total Sales & Marketing Cost / New Customers | Determines sustainability of growth. | | Behavior | Conversion Rate | (Conversions / Total Visitors) x 100 | Measures funnel efficiency. | | Behavior | Abandonment Rate | (Carts initiated - Purchases) / Carts initiated | Identifies friction in checkout. | | Monetization | Average Order Value (AOV) | Total Revenue / Number of Orders | Measures upsell/cross-sell success. | | Monetization | Customer Lifetime Value (LTV) | (AOV x Purchase Frequency) x Avg Lifespan | Tells you how much to spend on CAC. | | Retention | Churn Rate | Customers Lost / Total Customers at Start | Predicts revenue erosion. | | Financial | ROMI (Return on Marketing Investment) | (Incremental Revenue - Marketing Spend) / Marketing Spend | The ultimate efficiency ratio. |

Using cluster analysis to identify high-value customer groups.