This document discusses factors that influence consumer purchasing decisions. It describes the consumer decision process, which involves problem recognition, information search, evaluation of alternatives, purchase, and post-purchase behavior. It also outlines several personal, social, cultural, and psychological factors that can impact what and why consumers buy, such as social class, reference groups, age, occupation, personality, learning, and motivation. Reasons why people buy include practical needs, psychological needs, social status, popularity, and rational vs. irrational motivations. Understanding consumer behavior can help with market segmentation and positioning strategies.