We continued studying graphs with social networking applications in mind. We read a paper with obvious importance to social networks, “Opinion maximization in social networks” by Aristides Gionis, Evimaria Terzi and Panayiotis Tsaparas. This paper described a game theoretical method for choosing members of a social network who can spread a change of opinion most efficiently through the network. In other words, the paper describes a mathematical theory for how to find social influencer for a marketing campaign, or public relations campaign.