Post-war advances in technology have changed the concept of marketing management considerably. The core of this change is the shift of emphasis from the firm to the buyer. In this survey article, the author reviews all the important approaches to understanding buying behavior and provides an up-to-date bibliography. Two important issues emerge from the review. First, the existing variety of formulations resembles the variety of responses of seven blind men touching different parts of an elephant and making inferences about the animal which necessarily differ from, and occasionally contradict, one another. Second, the theory which attempts to explain the observed phenomenon of buying behavior and the quantitative techniques which provide adequate definitions and measurements have been developed independently of each other to the detriment of the maturity of the discipline.