Newt Gingrich announced that he is running for president this week in a tweet: a short message on Twitter, where all messages can't be longer than 140 characters. Mr. Gingrich included a link to a YouTube video.
Tweets and other social media platforms have become their own media. Jokes and gossip, to be sure, built a lot of Twitter followings. But reporters and politicians now use it because tweets can reach millions of people almost as quickly, and more directly, than even radio or TV can.
You've probably heard about the Awful Tweets About Japan That Got People Fired. Mississippi governor Haley Barbour's press secretary wrote one. Comedian Gilbert Gottfried wrote a whole bunch of them, costing him a cushy gig with the insurance company Aflac as the voice of their bespoke duck.
(And yes, a lot of people wrote and tweeted insensitive things about Japan that didn't get them canned, including 50 Cent and Rush Limbaugh.)