This document discusses measures, metrics, and key performance indicators (KPIs) for tracking business performance. It defines measures as anything that is measured, metrics as values derived from combining measures, and KPIs as the most important metrics for understanding if an organization is on track. It recommends measuring values that provide insight into the business, customer behavior, strengths, and weaknesses. The document also outlines the "Pirate Metrics" model of measuring acquisition, activation, retention, referral, and revenue, and how to track these metrics by traction channel to understand where customers are coming from. It stresses identifying the 3-5 most important KPIs that the business is willing to invest heavily in improving.