I’m quoting myself, in a comment on the brilliant and humane Brain Oberkirch’s blog:
I was in total agreement when I first read this post; for some reason I came back around to it (because you’ve been too quiet–too busy I bet) and now I have an additional thought about all this twitter-handle-as-identity. There is a weird paradox about twitter in that I can learn the most about you, and the least about you, over twitter.
If you are a stranger I can learn that “Oh, I’m really interested in you!” or “Oh, I’m not really that interested in you.”
If you are a friend, I can learn “Oh, you like asparagus too?!” or, “You’re at the hospital? What can I do to help?”
It comes back to the low threshold of the information, its ambient nature. I can choose to ignore it quickly, or retain it and take action on it equally as fast.
Back to your original point, it is the stranger case. I meet some people at a conference, I follow them on twitter. Within a few hours or days I have an idea if this is going to go anywhere. While going to their site and emailing them or subscribing to their blog’s RSS feed might have taken a significant amount of attention and energy, a quick “follow brianoberkirch” sent from my phone is low cost and allows me to quickly start making very small decisions about what the future might hold for this initial, awkward, short social transaction.