Social Media is definitely an added asset to a company if they play it well; some of the Top Fortune 500 Companies have done an exceptional job when it comes to Social Media.
Google has about 4,350,098 followers, the highest Followers on Twitter among the Fortune 500 companies
While Coco-Cola has about 40,094,541 Facebook fans as on February 2012
Check out more of the Social Media Statistics for Fortune 500 companies as on February 2012