Retention rate, or app retention, is a crucial metric in mobile marketing that assesses the percentage of users who continue using an app over a specific period following installation. It serves as a key indicator of user engagement and the efficacy of a mobile marketing strategy. This metric holds particular significance for subscription-based models and app/game developers dependent on advertisements. By monitoring and enhancing retention rates, businesses can optimize user acquisition efforts, refine app features, and secure long-term success.