The document discusses the difference between metrics and key performance indicators (KPIs). It states that a KPI is a specific type of metric that is important for measuring organizational goals, is decided by management, and leads to action. The document provides examples of online marketing KPIs such as ad click-through rate, cost per new subscriber, web customer interactions, and look-to-book ratio. It emphasizes that developing the right KPIs is important for maximizing organizational performance.