This document discusses influence and how it is measured by Klout. It defines influence as the ability to drive action and explains that Klout measures influence through network analysis and social actions like clicks, conversations, and shares. Klout assigns all users a score from 0 to 100 to indicate their level of influence, which is determined by factors like true reach and network amplification. The document then provides an example of how Klout identified influential users to promote a new Virgin America flight route, generating over 5000 tweets and reaching millions of people.