Gilles Raymond's white paper, "The Big Lie in Digital Analytics," addresses the significant issue of data loss in digital marketing due to browser privacy features, ad blockers, and consent prompts, which result in 25-40% of real customer sessions and conversions being omitted from analytics and advertising platforms. This omission leads to skewed return on ad spend (ROAS) calculations, misaligned bidding algorithms, and unreliable experimental tests. The paper suggests that conventional methods such as server-side APIs and modeled conversions fail to fully bridge the gap in data accuracy. Instead, it proposes a first-party, edge-side, consent-aware approach to enhance visibility and accuracy in data analytics, integrating seamlessly with existing tools like GA4. Supported by real-world case studies, this methodology promises to uncover hidden traffic and improve ROAS for B2B, e-commerce, and media brands, while the implementation is reportedly achievable within weeks. The document offers a vendor-neutral evaluation checklist and targets CMOs, marketers, analytics leaders, and privacy teams seeking to enhance data measurement and strategy, urging them to move beyond partial truths and optimize their digital marketing efforts comprehensively.