I was just telling my beloved that it is sort of like communal living in the modern age. You know all the news as it happens. You know what people are making for dinner and can seek advice on any subject from a wide range of friends. You see a friend's status update about their new vitamix or favorite read and your world is bigger.
Most of my life is spent in a small bubble of experience mostly centered around my three boys. Talking on the phone is a huge treat because I have to do it when kids are sleeping or watching tv. Some days my only adult conversation is the few minutes I chat with parents at kindergarten drop off. But on Facebook I can chat with my friend in Poland or Oregon all in my pajamas and they can't hear the kids screaming and if I get interrupted, I just catch up after I referee the Wii battle.
And don't get me started on all the games you can play. I have lost many hours of my life trying to beat someone's high score on Word Twist or Scramble. And if you like Scrabble I am always up for a game.