Before revision:  In this setting, we study a novel problem ofsocial welfare maximization : given item budgets, find an optimal allocation of items to seed nodes that maximizes the sum of expected utilities derived by users when the diffusion terminates .
After revision:  In this setting, we study a novel problem of : given item budgets, find an optimal allocation of items to seed nodes that maximizes the sum of expected utilities derived by users when the diffusion terminates .