In this paper, the authors anatomize incentive structures in peer assisted services with multiple content providers and focus on stability issues from two different angles: stability at equilibrium of Shapley value and convergence to the equilibrium. They first define a coalition game in a peer assisted service with multiple content providers by classifying the types of coalition structures as separated, where a coalition includes only one provider, and coalescent, where a coalition is allowed to include more than one provider. They show that the Shapley payoff scheme may lead to unstable coalition structure and propose a different notion of payoff distribution scheme, value, under which peers and providers stay in the stable coalition as well as better fairness, is guaranteed.