The rich-club is a closely connected sub-community in networks that has important impacts on the online information diffusion. To investigate the rich-club effect in information diffusion on social media and its origins, we studied the mechanisms of information diffusion on the biggest microblog of China—Sina Weibo. The results demonstrated that there are obvious rich-club effects in both influential users and randomly sampled users; For the information diffusion within the rich-club, social selection, geographic proximity, and social influence were found to have significant influence, and the impact of social influence is overwhelmingly strong. The findings outline the landscape of information diffusion on Microblogs and the theoretical generalizations help us understand the hierarchical feature of rich-club phenomenon in information diffusion.
Under review.