Explain 'North Star Metric'

The North Star Metric is the single most important measure of product success, representing the core value a customer receives from using the platform. It serves as a guiding light for all teams, ensuring every feature and initiative directly contributes to that central goal. For LinkedIn, a strong North Star Metric would be 'Monthly Active Professionals who send at least three meaningful connection requests.' This works because it captures active engagement that leads to tangible career outcomes, which is LinkedIn's true value proposition. Conversely, a poor North Star Metric would be 'Total Registered Users.' While registration numbers look impressive, they are a vanity metric; a registered user who never logs in or connects provides zero value to the ecosystem. Focusing solely on registrations encourages spammy sign-ups and ignores whether the product actually helps people find jobs or network effectively. By anchoring on meaningful connections, LinkedIn ensures its engineering, marketing, and sales teams are all aligned toward fostering genuine professional relationships rather than just inflating headcount statistics.