The "Great Thinkers in Marketing" series highlights the significant contributions of the most influential scholars to marketing research, theory, and practice. The series and volume editors organize each legend's most impactful articles into several volumes as an anthology set. Volume editors also seek commentaries from other scholars familiar with the legend's work on the articles included in that volume. This set, comprising six volumes of contributions of Donald Lehmann, covers a broad spectrum of topics relating to customer behavior and decision-making processes, the estimation of stochastic models, empirical replication for theoretical generalization, advertising and branding, new product and innovation diffusion, and performance outcomes of marketing strategy. This volume, edited by Jeffrey Parker, highlights the conceptual and methodological diversity found across Lehmann's research on consumer behavior. Along with a collection of his articles related to the topic, it features an interview with Lehmann himself and three insightful commentaries from his frequent co-authors. This work demonstrates Lehmann's dedication to utilizing research to tackle significant real-world marketing challenges, offering valuable insights for academics and practitioners.