Form in writing  — essay, novel, poem, tweet— shapes thought so it aligns with its function to engage a reader. A tweet, as a form, is a mouthful, more or less one breath. Its forum, the twitterverse, is anyone on twitter. A tweet’s function is to gain a following through commenting. A tweet, with its 140 character limit and unfiltered nature, is communication with high consequence — which makes its practice both seductive and dangerous. Tweets are “thinking in public” and have become if “not required reading, required writing” as Thomas Beller asserts in his essay: The Ongoing Story, The New Yorker (2013). Beller states, “one of the central paradoxes of our culture is everything is swallowed into oblivion but nothing goes away.” Tweeting as speech is akin to spit. The word spit conjures up its essential nature: a projectile, something set to burning, something that impales. But also, like spit, tweets are street detritus, throwaway but indelible at the same time — so, a perfect form.

http://www.newyorker.com/books/page-turner/the-ongoing-story-twitter-and-writing