For the last five years the University of Massachusetts Dartmouth's Center for Marketing Research has been conducting a study about the use of social media in the 500 fastest growing organisations in the US (The Inc. 500.) The first study, conducted in 2007, found that these companies were much more likely to have adopted blogs than those in the ‘traditional' Fortune 500.The latest findings show that the use of blogging in the Inc. 500 companies is declining for the first time. Blogging had declined to 37% from 50% in 2010. Advertising, Marketing and Media companies were the most likely to maintain blogs (72%) and Government Services companies the least likely.However, as blogging reaches maturity in these organisations, the use of other social media, including Facebook, Foursquare, LinkedIn, Mobile apps, texting, Twitter and YouTube, is growing. 74% of responding companies were using Facebook, and 73% using LinkedIn.90% of respondents report that social media tools are important for maintaining company reputation and raising brand awareness. Slightly fewer see the tools as vital for generating web traffic and lead generation. 73% say the tools are important for customer support programmes.When asked if the use of social media has been successful for their business, the overwhelming response was that it had been. Respondents mentioned raising brand awareness, networking, thought leadership and the tools' ability to give the company a ‘personality'.25% of respondents plan to maintain their organisation's investment in social media, and 71% plan to increase it.The report is data rich and interesting reading. It shows that the use of social media in organisations is evolving, with some mature tools being dropped in favour of newer ones. A recognition of their value in supporting networking, and new ways of communicating, means that many organisations are planning to increase their investment in social tools.