This study delves into three fundamental theories of social media: Hofstede's Theory of Cultural Difference (personal behavior), Social Influence Theory (social behavior), and Media Richness Theory (mass communication). It examines how these theories impact individual and collective behavior in the context of social media, highlighting their strengths, weaknesses, and applications in various settings. The analysis provides a comprehensive understanding of the theoretical underpinnings of interactive marketing and its implications for businesses and individuals.