Klout is an online search program that collects data related to individuals who are engaged in online activity (social media) and gives them a rating according to predetermined criteria. Klout considers how many people you influence (your true reach), how much you influence them, and how influential your friends and followers are. This gives you information on how influential you are in your particular areas of interest. Being more influential can lead to "perks" where brands in your area of influence may give you products hoping you will give them a favorable review. Basically, Klout measures the degree of influence your posts (blogs, updates, retweets, etc.) have online.