Propose a North Star Metric for a product you know

WHAT IT TESTS: Whether you can identify the single metric that captures core customer value and predicts sustainable business growth. A GOOD ANSWER COVERS: a crisp definition of the North Star as the one measure of value delivered to users; a specific metric for a real product such as Spotify or Slack; and the causal chain showing how user value drives retention, engagement, and long-term revenue. RED FLAG: Proposing a lagging revenue metric like ARR or a vanity metric like total signups that ignores whether users actually experienced value.