1. A method to determine a first network efficacy, comprising: accessing, using a processor, interaction data and contact data for a user of a first social networking site via an interface provided by the first social networking site; determining, using the processor, a connectedness for the user based on the contact data; determining, using the processor, an interactivity for the user based on the interaction data; determining, using the processor, a network constancy for the user; and determining, using the processor, the first network efficacy of the first social networking site based on the connectedness, the interactivity, and the network constancy.