1. A method of determining a seed group from a plurality of users, wherein the seed group is operable to disseminate content across a communication network connecting the users when the seed group is targeted with the content, the method comprising: predicting an influence of a user disseminating the content to the plurality of users; iteratively adding the user to the seed group if the influence of the user exceeds a threshold; and if the user is added to the seed group, adjusting probabilities of other users of the plurality of users disseminating the content to the user in order to adjust influence of the other users.