I use them in complete different ways
FB : Use my full name Very conservative in what I post. Use to keep in touch from people in my past. including high school, college, ex works and ex neighbors i join groups of common interests like biking group. It is very superficial and generic. My PM's on facebook are mostly "how is your life going emails"
SW: I am anonymous and don't really have an image to protect. I can ask or respond to more sensative topics. Some of my PM's on here are like my FB PM's and some are much deeper or topics I wouldn't talk about on FB
LinkedIn : you did not put LinkedIn on here but I guess it sorta fits. Just for business. Network, make business connections and nothing else. I am friends with some of my LinkedIn connections but it was almost always that we shared an employer in the past. I send happy bday emails on LinkedIn but almost never anything else.
I have over 2000k LinkedIn connections about 450 FB and well under 100 on SW.
