Understanding the Influence of Social Hubs in Diffusion Processes Driven by Incentivized Friend Invitation

With the prevalence of social media, rewarding users to invite their friends to use an application or adopt a service has become one of the most successful designs in recent years. As the application or service spreads, a diffusion process driven by incentivized invitation forms. However, despite the extensive attention from both industry and academia, this newly-emerging diffusion process remains under-explored. To bridge this gap between academic research and industrial practice, we set out to examine the influence of social hubs, i.e., people with a considerable number of social ties, in the diffusion process driven by incentivized friend invitation. Through a large-scale empirical data analysis, we found that under three different measures, the influence of social hubs on the growth of the diffusion process is saturated as their number of contacts increases. Following this observation, we further explored possible causes of this phenomenon by a mixed method that combines a large-scale empirical data analysis and a semi-structured interview to deepen our understanding of social hubs’ influence in the diffusion process. We revealed two main causes. First, large social hubs lacked the will to keep engaging in sending invitations, and the anchoring effects on the cost-utility trade-off could explain their behaviors. Second, social hubs’ broadcasting capability decreased in the invitation-based diffusion process because hubs are better at informing rather than persuading compared with non-hubs. Our findings provide in-depth insights into the understanding of the nature of social hubs’ influence, and we further discuss practical implications for designs to facilitate invitation-based online diffusion processes.