Net Retention Rate (NRR) is a crucial revenue metric that calculates the percentage of revenue retained from existing customers, including upsells, cross-sells, and renewals, while accounting for downgrades and churn. A high NRR indicates that a company is expanding its revenue within its existing customer base, reducing reliance on new acquisitions. SaaS and subscription-based businesses use CRM platforms to track retention trends, measure customer expansion revenue, and identify at-risk accounts. Improving NRR requires strong customer success programs, proactive engagement, and data-driven upsell strategies. Companies with an NRR above 100% are experiencing net revenue growth from their existing customer base.