Metrics are measurable values that help businesses evaluate the performance of a product, feature, or activity. However, not all metrics are meaningful — some can be irrelevant or misleading if not aligned with business goals. In product interviews, candidates are often asked how they would measure the success of a feature, which requires a clear understanding of metrics, their fluctuations, and how to identify the root cause behind any unexpected changes.

Key Performance Indicators (KPIs) are a subset of metrics directly tied to business objectives. They help track progress toward specific goals and support strategic decision-making. Common KPIs and metrics include Customer Acquisition Cost (CAC), Customer Retention Rate (CRR), Feature Usage, Customer Conversion Rate, Monthly/Annual Recurring Revenue (MRR/ARR), and Net Promoter Score (NPS). Each of these offers valuable insights into customer behavior, product performance, and overall business health.

Additionally, metrics like A/B testing and customer feedback analysis help product teams make data-driven improvements. Listening to users and measuring satisfaction through NPS, interviews, and conversion data ensures that businesses not only acquire new customers but also retain and engage them over time. Choosing the right metrics is crucial to driving product success and sustainable growth.