With 11 grandchildren, 2 kids and 3 step kids, two brothers, and a dozen or so cousins, etc. - all spread out over a dozen or more states from one ocean to the other - FB seems to be the tool to keep us all up to date. Since joining FB my communications with my grand kids have grown exponentially. Posting pictures keeps us linked on each others going's on and makes the distance between us seem less like a barrier.
I've also managed to touch base with about 50 former classmates and a couple of dozen former colleagues.
I disdain the games and polls and do not participate in any of them. I use an add-on called 'Better Facebook" that helps me weed through the garbage and opt out of all sorts of nuisance applications and polls.
I've recently joined Google+ and I think I may start participating more there. Just watching and adding a few friends to my circles for now.