I think you hit it on the head at the end of your post. His status as a nerd celebrity essentially ensures that many of the connections he has via these social

I think you hit it on the head at the end of your post. His status as a nerd celebrity essentially ensures that many of the connections he has via these social networks will be tenuous at best. You can't classify the connection you have a to guy who's heard your podcast the same as your good friends and co-workers (or your wife! ;)). This will sound conceited, but I think most people I'm associated with via Twitter would probably care if I disappeared without a peep for more than 5 days. So I think that while most people don't really care about his tweeting, nearly every other user's connections to their followers/followees will be much tighter.