1. A method of sending one or more signals, which method comprises, in combination: (a) using one or more networks to gather network data, which one or more networks include node devices, and which network data includes data that is indicative of communications among at least some node devices, and (b) using electronic components to send the one or more signals to a subset of human users of the one or more networks, wherein the subset comprises human users selected using an algorithm performed by one or more processors, and the algorithm comprises (i) using the network data to calculate a plurality of graphs, (ii) using the plurality of graphs to calculate a composite graph, (iii) using the composite graph to compute conditional probabilities, each of the probabilities, respectively, comprising a probability that a human user will engage in a specific behavior, and (iv) using the conditional probabilities to select the subset of human users.