How Many Followers Can One Person Handle?

It seems to be a hot topic in the past few days.  Is it good to have a lot of followers on Twitter, or just a few?
I was first intrigued by the video blog of Steve Witsen.  He likens having a great many followers to trying to make an announcement to everyone at a U2 concert.  You'd have a lot of people to tell your message to, but most of them wouldn't listen.  Nor would they care.
By having a couple hundred (or less!) dedicated followers who are truly interested in what you have to say,  you target your message to those for whom it is relevant.  Lightbulb moment!
Another worthy blog that shares this sentiment and expands on it is that of Aliza Sherman on WebWorkerDaily (10 Things to Avoid in Social Media).  #8 goes a little something like this:

"Avoid the numbers game. Sure you can use automated following tools and maybe get a slew of people following you back. But they’re not listening. They don’t care. I’ve always said that I’d rather have 100 friends, fans or followers who care than 1000 who ignore me.  Social media is not about the big numbers but what you do with the numbers you have — and what they do in return. Devoted actions of a few can have an exponential impact, far greater than inaction by many."

This game seems to change daily, so keeping up with it is at turns exhilarating and exhausting.  But somehow, the conventional rules of social interaction and traditional etiquette still hold. (Thankfully)  Building relationships and trust takes time and attention.  Or as we used to say "If you want a friend (follower, tweep, connection, link...) , be a friend."