That's the thing. You can't force anybody to follow your twitter feed. Only people who WANT to know what you're doing in minor increments will follow your feed.
Who says that 'social' has to equal face-to-face time? Face-to-face time is not terribly easy to get, what with having to actually travel to your friend's location. Twitter is the same as calling a friend and telling them what's going on every once in a while, except it's opt-in. Only people who WANT to know what's going on in between face-to-face meetings will follow your twitter feed. Everyone else can just wait to sit down with you to find out.