Here is an interesting comparison of Twitter and blogs:
Blogging was a direct attack on MSM hegemony at both the micro (fisking) and macro levels (explanation space). I just don’t see Twitter as the same threat. It is a flood of unmermorable chatter that is easy to ignore. Blogging had the potential to break the power of the MSM guild. Bloggers, at their best, presented arguments. Arguments can both change minds on the immediate subject and undermine the credibilty of those establishment pundits who present weak cases on a regular basis.
I think that’s largely apt, but there’s more to it. Both blog posts and tweets tend to be short, but tweets are too short to convey any real content or argument. It’s the difference between e-mails and text (sms) messages. There’s no inherent cap on e-mail length, but e-mails are kept short. Text messages are capped at 160 characters. With Twitter, there is no way to convey a complex idea in only 140 characters.
Blogs-and the web generally-permit authors to reach a much wider audience than they could otherwise–essentially disintermediating the gatekeepers of old. Twitter is too short and is a closed system, so it cannot achieve the disruptiveness of blogs.