Would you rather have your business be profitable or popular? Much of what companies do in social media marketing is aimed at becoming popular. If you have more friends or fans, you are more popular. If you have more subscribers or commenters, you are more popular.
Each social media tool has it’s own way of working, both technically and culturally, and requires a unique approach for each. Twitter has evolved as a great place for news, entertainment, updates, and general chit-chat. Facebook is great for forming (or rekindling) relationships, social gaming, and socializing. LinkedIn is all about business networking and job fulfillment. What goes on in one platform is generally ill-received on others.
Lynette Young, founder of Purple Stripe Productions LLC, recommends a written agreement between the employees and company that outlines roles and responsibilities, including topics and issues that are and are not permitted to be covered in a public forum such as blogging or social networking, as well as a process to get information not covered accepted and approved.