This document summarizes key points from a presentation by Ziya Boyacigiller on circumstance-based segmentation. It discusses how most new products fail because companies define segments based on customer demographics rather than the circumstances or "jobs to be done" when customers make purchases. Circumstance-based segmentation involves understanding the alternatives, pains, and functional/emotional needs customers have when they encounter different circumstances. Defining segments this way allows companies to create products that truly meet customer needs and pain points.