As marketing becomes increasingly data-intensive, organizations require robust reporting systems anchored in Key Performance Indicators (KPIs) to track, optimize, and scale high-growth campaigns. This paper presents a comprehensive literature review on the design and deployment of KPI-driven reporting frameworks tailored for digital marketing contexts. It explores the theoretical underpinnings of performance measurement, evaluates technology stacks enabling real-time analytics, and synthesizes industry best practices. A conceptual model is proposed for structuring KPI-driven reporting workflows, emphasizing data governance, automation, visualization, and alignment with strategic business goals. Drawing on over 100 sources, this study underscores the criticality of actionable metrics in navigating marketing complexity and offers a roadmap for future research in data-driven campaign optimization.