Product managers are encouraged to track product metrics to make informed decisions and drive value for customers by identifying which features are popular or underperforming, understanding user engagement, and gauging customer satisfaction. Key metrics often include retention, engagement, and conversion, but these should be tailored to the unique goals and industry of a business, as there is no universal metric. Differentiating between input and output metrics is crucial, with input metrics serving to influence output metrics such as retention. For effective tracking, product analytics platforms like Mixpanel offer tools for managing metrics, generating reports, and conducting A/B tests, ultimately transforming measurement into a tool for effecting change and improving product management.