For the third consecutive year, the Center for Marketing Research at the University of Massachusetts Dartmouth has conducted a study that looks at the usage of social media among Inc. 500 companies. The 2009 results confirm thatAmerica‘s fastest growing private companies adopt social media marketing initiatives at much higher rates than other companies, and that interest in social media has grown since the first study was conducted in 2007. Of the social media platforms studies, Twitter was the most widely used among, drawing activity from 52 percent of the respondents. Respondents were asked if they were monitoring mentions of their company name or their brands on social media sites, and 68 percent said yes, compared with 50 percent just two years ago. 34 percent of companies reported that they were using social media to communicate with vendors and suppliers; 26 percent cited Twitter in particular as an important vehicle for communication with outside partners. Article at Inc.