This book integrates two related fields of study, learning and expertise, as they have been applied to consumer behavior. The first part of the book focuses on two central hypotheses that are seldom explicitly endorsed or rejected. In the normal course of everyday life, consumers become increasingly familiar with the products and service that they use. Possibly, over time people learn from these experiences and gain true expertise in a variety of product domains. Thus, the first hypothesis that increased familiarity leads to increased expertise: learning from experience (H1). Second, it seems reasonable that as expertise increases, people become more efficient consumers: increased consumer welfare (H2). The authors' analyses reveal that these hypotheses are often, but not always supported, and sometimes opposite results obtain. The remaining parts of the book provide systematic reviews of the theories, methods, and applications that have been prominent in research on consumer learning and expertise.