True Reach is the size of your engaged audience and is based on those of your followers and friends who actively listen and react to your messages. Amplification Score is the likelihood that your messages will generate actions (retweets, @messages, likes and comments) and is on a scale of 1 to 100. Network score indicates how influential your engaged audience is and is also on a scale from 1 to 100. The Klout score is highly correlated to clicks, comments and retweets.
Klout is enabling businesses to do more than "get followers" but to know the INFLUENCE of those followers - much more important in the long run.