What is Klout?
Klout is a website and mobile app which measures your online social influence on a scale between 1 and 100. The top end of the scale is reserved for ubiquitous online presences like Google (98) and eBay (94). Us mere mortals aspire to #Klout70, a rank which tells the world you're something of a social media expert.
My Klout score.
Do I have Klout?
Everybody with a public Twitter account already has a Klout score, you just need to sign up to the website and claim your account. If you don't have a public Twitter account, Klout will work out your score based on the other accounts you connect to it. The average Klout score is 40, and bloggers, just by virtue of all the social media interaction and promotion which comes along with the territory, average in the 50s. If you score 68 or above, you're in the top 5% of all Klout users.
How is my Klout calculated?
Klout pulls data from Bing, Facebook, FourSquare, Google +, Instagram, Klout, LinkedIn, Twitter, and Wikipedia to measure your online influence. The metrics are far from perfect, but it does give a rough idea of how big of a deal you are on the net.
You can connect other networks, although how much this will affect your Klout score is a bit of a mystery. Klout says it definitely won't decrease your score, so you won't lose anything by adding all your accounts.
Does Klout Matter?
How important your Klout score is heavily depends on who you ask about it! Some brands do request it, to help them decide which bloggers to work with, and a high score always looks impressive. Its real importance, to my mind, is the weight Klout carries in other scores: it is a factor in your Tots100 rating, for instance, and it plays a part in determining how well you do in Bing's search rankings.
So, while it's not essential, it is something well worth cultivating if you're looking to be considered a top 'influencer'.