title: Emergence of scale-free leadership structure in social recommender systems.
abstract: The study of the organization of social networks is important for the understanding of opinion formation, rumor spreading, and the emergence of trends and fashion. This paper reports empirical analysis of networks extracted from four leading sites with social functionality (Delicious, Flickr, Twitter and YouTube) and shows that they all display a scale-free leadership structure. To reproduce this feature, we propose an adaptive network model driven by social recommending. Artificial agent-based simulations of this model highlight a "good get richer" mechanism where users with broad interests and good judgments are likely to become popular leaders for the others. Simulations also indicate that the studied social recommendation mechanism can gradually improve the user experience by adapting to tastes of its users. Finally we outline implications for real online resource-sharing systems.
authors.affiliation: Web Sciences Center, University of Electronic Science and Technology of China, Chengdu, People's Republic of China. zhutou@ustc.edu
authors.forename: Tao
authors.initials: T
authors.lastname: Zhou
authors.forename: Matúš
authors.initials: M
authors.lastname: Medo
authors.forename: Giulio
authors.initials: G
authors.lastname: Cimini
authors.forename: Zi-Ke
authors.initials: ZK
authors.lastname: Zhang
authors.forename: Yi-Cheng
authors.initials: YC
authors.lastname: Zhang
mesh_terms: D003198:Computer Simulation; D036262:Empirical Research; D020407:Internet; D007600:Judgment; D007857:Leadership; D008962:Models, Theoretical; D015203:Reproducibility of Results; D012944:Social Support