Some key metrics on what to expect from Social Media:
The key takeaway I found was something both Hester and David Rogers of Columbia Business School mentioned as standards for social media participation. They called it the 1/9/90 rule. With blogs, message forums, user-generated content, or other social media tools, 1 percent of users will be “super users,” generating their own content, coming up with new ideas, and constantly sharing their thoughts. Another 9 percent will be “active users” who comment once in a while. The last 90 percent will be “passive users,” taking in all the information available, but never commenting themselves. “This is very important because it allows you to set expectations of user activity and even predict ROI,” Hester said.
via Managing Social Media’s Expectations – Think customers: The 1to1 Blog .