Klout, a start-up that provides a social credit score for more than 100 million public profiles across various social networks, raised a C round of financing of around $30 million, reports Business Insider. The company has more than 4,000 API partners -- up from around 100 in early 2010, notes TechCrunch. A few million people have actively registered on Klout.com in order to tie their various social profiles together.