Abstract: Based on net interest margin group perspective to study the knowledge characteristics of paid products and user demand, found that users use knowledge demand pay product was the use of fragmented time to accumulate interdisciplinary knowledge and skills, in order to solved the knowledge anxiety, screening high quality content and services, access to experted in the field of cognitive and insight, seek sentimental, relieve the huge pressure from society. By referring to the typical case of knowledge payment product demand to meet the design, put forward the knowledge payment product development Suggestions.

Key words: internet interest-related group, knowledge paid, user demand