Long-time blog-neighbor T/R/P is contemplating Twitter. Sort of. More accurately, he's contemplating blogger burnout, and leaving Twitter for the far-off future as a fallback plan.
How can a blogger avoid burnout? I see at least two routes to successful long-term blogging. First, continuous posting to build up a fanbase. This either takes financial independence or a team effort. Second, for the individual hobbyist, a slightly more random version of the same, with enough posts per week to people coming, but with enough unpredictability to keep things interesting. (Think "variable schedule reinforcement," the true joy of gambling.)
I used to write short posts on this blog, since it was the only place for 'em. Now I save my inner Hemingway for Twitter--which shows up on the blog sidebar, for your enjoyment--and save a little space between blog posts.
Blogging and Twitter don't have to be an either/or. Like man and fish, they can coexist peaceably.
Related: the two Slate pieces that got me thinking about how to Twitter better: the one about orphans and the one about blowhards.