Reaching business users is very difficult: they are generally older and not active on social networks with the exception of linked in. However, few people are "active" on LI except marketers and job seekers. I run a service in the corporate/legal that relies on invites from existing users to get new users. We decided LI integration was not a good use of time. When I have posted content in LI groups I notice very low click through, regardless of the nature of the content.