Twitter and Conversation Analysis: Who's Here?

I believe that phone conversations for customer support have been studied quite a bit -- looking for phrases that sound like triggers for anger, avoiding long pauses, and when one party overtakes a phone conversation, it's relatively easy to detect when that's happening. But with Twitter, you could have long pauses intentionally as asynchronous, IM-like conversations happen when someone gets up from their desk and returns after a business meeting, for example. Neither party is angry about that long pause, it's just an understood agreement in the Twitter medium that you may or may not be immediately responsive. How does that time factor change the 'agreement' for a support exchange?

Gentle, Anne. Just Write Click (2009). Articles>Collaboration>Social Networking>Help