The document discusses the importance of measuring cohort retention to determine if a product is truly gaining traction. It defines cohort retention as the percentage of people who performed an action, like using an app, and returned to perform the same action again within a set time period, usually a week. It notes most other metrics like downloads or users are not good predictors of success. The document advises that a retention rate above 25% could indicate the product is gaining true traction, while lower rates mean the product is not sticky enough and more work needs to be done to improve value and engagement. It provides a framework to categorize products based on how addictive and valuable they are to help focus on driving the right viral and conversion metrics to improve cohort