I haven't thought about what Twitter is for years. Once something becomes a tool in your life, you stop thinking about the meaning of the thing and just use it. I do not often find myself pondering the meaning or utility of a fork; I just eat.
But that changed a few days ago when Google Plus launched. I know I've been writing about it incessantly -- to the chagrin of some readers (sorry!) -- but I think it's conceptually important, whether or not it succeeds. When a new social network launches, it gives us a different basis for comparison. New things are thrown into relief. In short, the quality and depth of the comments on Google Plus have made me reevaluate Twitter as a conversational tool.
You often hear that Twitter is a good conversation platform because people interact with each other a lot, and every so often, people trade four or five Tweets back and forth.
But Twitter isn't good at conversation, per se. Twitter is good at call and response, or what I'll call "an idea barter." Interactions on Twitter often take the form of quid pro quo. You quip, I quip back. You post a link, I post an answering link. You ask a question, I respond. You call, I respond. But it's not really a "conversation" as anyone has ever understood that word.