In the dynamic landscape of ecommerce, multi-channel promotions have become essential for reaching and engaging customers effectively. However, measuring the impact of these promotions across various platforms presents significant challenges. This paper explores how artificial intelligence (AI) and data science techniques can be leveraged to accurately measure and optimize multi-channel promotional efforts in ecommerce. The importance of multi-channel promotions and the challenges associated with their measurement, including attribution complexity, data silos, and privacy concerns are highlighted in this article. It then delves into how AI and data science offer solutions to these challenges, discussing advanced techniques in data collection, integration, and preparation. Key areas explored include AI-driven attribution modeling, machine learning algorithms for customer segmentation, and predictive analytics for promotion optimization. The paper also examines the role of AI in enabling real-time monitoring and adjustment of promotional strategies, including anomaly detection and dynamic pricing. Ethical considerations and future trends in the field are addressed, emphasizing the need for privacy-preserving techniques, unbiased algorithms, and explainable AI. The article concludes by underscoring the transformative potential of AI and data science in enhancing the effectiveness of multi-channel promotions in ecommerce. This comprehensive review provides valuable insights for marketers, data scientists, and ecommerce professionals seeking to leverage AI and data science for more effective measurement and optimization of multi-channel promotional strategies