Sharif Digital Repository

In this researh, we study the problem of profit maximization using viral marketing in social networks. In our model, the individual’s ultility value consists of two parts: a private utility and a value obtained by effects of other network members. Each member selects the service that maximizes its utility and Server can exhibit services in different qualities. First we focus on the problem from the Game Theory viewpoint and discuss on the existence and optimality of equilibrium. Next, we show that finding the best equilibrium is NP-hard. For the case of two services, we show that while P ̸= NP, no approximation algorithm with factor better than 2 exists for this problem. Finally, we try to...