Book excerpt: This book helps marketing decision makers in allocating their budget to diverse communication channels and different business units in an ROI-optimal way, and to adapt it in an agile manner. The optimal allocation of resources in marketing is not very complex in theory, but in practice a variety of questions arise, for example: How do you find the optimal mix, even across brands and product lines, and how do you adjust it dynamically? What is the right balance between image and performance marketing? How do you tackle strategic data management and other organizational challenges? The authors guide the reader through the entire process from data collection to marketing mix modeling and campaign tracking to tool selection. The book strikes the right balance between theoretical sophistication and necessary pragmatism, with numerous concrete recommendations for decision makers.