This document discusses agile metrics and why they matter. It begins with an introduction to Erik Weber and his background. It then provides a brief history of metrics usage, comparing traditional and agile environments. In traditional environments, metrics were often used punitively with negative effects, while agile focuses on building quality in through practices like definition of done. The document cautions that the only metric that truly matters is customer feedback. It discusses the human side of metrics, like the Hawthorne effect, and suggests focusing on outcomes rather than outputs. Finally, it provides examples of agile metrics like sprint burndowns, velocity, throughput and happiness that can provide value when used appropriately.