I have to disagree with you on that. 140 characters forces one to be brief and to the point (I'd almost say creatively brief). Links can be sent through URL shorteners, and if you really need to write a long message, then Twitter isn't the proper medium anyways.
There's nothing "fragmented" about exchanges on Twitter for quite a while now. If you click on an @message, you can see the entire conversation chain in the sidebar.
IMO having a "real", deep conversation requires the ability to write long messages. Thus, as you say, Twitter isn't the proper medium for that.
Your statement of "fast" confuses me. Minimum roundtrip for a write/reply/read sequence on Twitter is something like a minute. A conversation that would take five minutes on IRC can take several hours on Twitter.
>IMO having a "real", deep conversation requires the ability to write long messages.
Your definition of "real" is deep and long? Okay then.
>Minimum roundtrip for a write/reply/read sequence on Twitter is something like a minute.
Not in my experience. When using software tied into the API, I've gotten maybe 5-10 seconds lag between entering an @reply and having the client be notified of it. This was while testing, curiously enough, an IRC bot and Tweetdeck.
I think that "real", especially in scare quotes, brings along an expectation of depth, yes. Depth then in turn requires the ability to write longer messages.
As for the roundtrip, that's interesting. Perhaps it's just the clients (or the clients I use) that are slow.
You say "creatively brief", I say "broken". When I read Twitter exchanges (and yes, I know about the conversation chain), it reads almost like quaint 19th century telegraph: full of shorthands, "creative" ways to be brief, unintelligible loss of grammar sometimes...
I've had way more, and better conversations on G+ and Facebook because it doesn't artificially force you to dumb things down (or possibly worse, resort to unintelligible TwitSpeak).
There's nothing "fragmented" about exchanges on Twitter for quite a while now. If you click on an @message, you can see the entire conversation chain in the sidebar.