Ranking of features in using Facebook for PA participation between two groups. Moneycontrol.com said it had seen a copy of an internal product brief that details the functioning and various product features of the app, but that it was not clear whether development had begun, though noting a source said it is still in progress. Who are the most popular, important, and influential people in these groups? These friends have high degree, betweenness centrality, and eigenvector centrality scores. High degree means that we share many friends, and are likely close to each other. High betweenness centrality reflects awareness of many different friends, and also indicates a close friendship in real life. Influence is indicated by high eigenvector centrality scores, where the person is friends with many popular people. For each group, these are the people to target with messages or invitations to events in order to maximize dissemination and participation among the members of the group.