Its more of a networking thing for me. With my coaching, my training and my gym I network with a lot of folks. Plus I have a whole other set of FB friends that revolve around the MMA that I am involved (licensed judge in the state of Ohio) And some are just folks who are fans of me and my lifting who ask me questions about my training and benching.
I can honestly say no I do not talk all 5000 plus but I do know a great deal of them personally from all the years of being in powerlifting and MMA.
Apparently you are putting your FaceBook account to good use. When I first joined FaceBook, I had all these strangers asking to be friends. I ignored them. Most of my FaceBook friends today are family and work related people. However, I don't have even 10% of the number of FaceBook friends you do. To be honest, my family is spread all over the world. If it were not for FaceBook, we probably wouldn't be nearly as connected as we are. For me, FaceBook has been a very positive experience.