I'm active on Reddit (imagine that!). Have Facebook account I haven't logged in for over a year or even more, can't remember. Never ever posted anything on said Facebook account, used it for various registrations and giveaway/promotion purposes. Have a single old image of me on it with some stupid filter applied. Also have G+ account which I've logged in maybe five times or so, useless thing. Youtube account I don't classify as social network but if you're leaving comments in there I guess it can be seen that way.
Instagram, Twitter, Snapchat - no accounts. Have linkedin account and use it only for what is meant for, to connect with business partners. Have Viber and use it to keep in touch with closest family. Also have Steam account which is active just like my Facebook account since I don't play video games anymore.
Even when Facebook was at its peak I've been telling everybody around me that is pure stupidity. However I did open Facebook account at some point because I needed it for something. Truly glad it is dying and hopefully Facebook will become irrelevant in few years time. Just like Myspace ended. I'm old enough to remember glory days of Myspace and early adverts for Facebook when it was marketed towards high school long lost buddies.