Which social media platform reaches more open networkers?

When I talk to people about social media, I start with LinkedIn which most networkers say they are members, but don’t know what to do on it. LinkedIn allows you to post pictures, videos and links.  You can also tag your connections just like tagging friends in Facebook.  It’s interesting to observe that most of my LinkedIn connections aren’t as chatty or active on LinkedIn as my Facebook friends.  In the past, most networkers were not on LinkedIn, so it’s good to see more on it now. I wish more would post more often and share more often.  Contrast this to Facebook where most are members and most  are using it regularly. Most every networker I know is already on Facebook.  I would say if you want to communicate with open networkers, you can try the LinkedIn, but don’t be surprised if you get no response.  Use Facebook to really reach them.  I don’t have anything scientific to back my hunch and I’d like to know what do you think?