Twitter also has this element of being like a river you can dip into whenever you're inclined and ignore the rest of the time. As you say, I do subscribe to some newsletters and mailing lists but it's very easy to get overloaded and/or end up filtering things to a folder that you never look at. Twitter seems to strike a reasonable balance of utility/effort/distraction/etc. for a lot of things that email-oriented methods really don't.
Ah right..
Like that story last week about the writer that got so addicted to twitter that she had to close her account?
From my point of view it doesn't seem so easy and balanced.
