Refers to the lack of consumers' physical and psychological state, that is, they feel that they are missing something and want it. Individuals will have various needs in the process of survival and development, such as the need to eat when they are hungry, the need to drink when they are thirsty, the need to be friendly and respectful when interacting with others, and the need to realize themselves.

Demand is closely related to human activities. People buy products and receive services to meet certain needs. When a demand is met, a new demand will arise. Therefore, people's needs will never be completely met and terminated. It is the infinite development of demand that determines the permanence and eternity of human activities.

Although necessity is the driving force of human activities, it is not always in a state of awakening. Only when consumers' sense of scarcity reaches a certain degree of urgency will demand be stimulated and consumers will be prompted to take action. For example, the vast majority of consumers in China may have the need to live in a more spacious house, but due to objective factors such as economic conditions, this demand is mostly hidden in the hearts of consumers and has not been awakened or fully realized. At this time, the influence of this potential demand or non-explicit demand on consumer behavior is naturally weak.