I see FB as a necessary evil to a degree - it's absolutely great to keep up with people who you'd certainly lose contact with otherwise and you do see some strange stuff BUT it's also like a window on the soul. It amplifies a persons personality - in some cases it's made me realise certain 'friends' are actually self centered twats.
I like to use FB for my art page, it means I can showcase my latest work or when a new design is available and 99.9% of followers are really cool and have become friends in some cases.
As for SW groups, again, there's folks who are great and help you out, and then there's complete tossers but such is life and whilst I do use them to buy and sell sometimes or to check out what other folks are buying this forum is without doubt the best place online to chat about vintage SW stuff - some great personalities and a great atmosphere, I'll always make sure SWFUK gets recommended first and foremost as the best place to join if you collect.