The average shelf-life of a tweet is about 48 hours. If no one has paid attention by then, your 140 character interludes about life, love, your parents, and your jerk of a boss fade off into the Internet ether. The news is mundane. However, sometimes tweets change the world, destroy careers, and make people go insane.
If you have lots of followers, or even a few big-name ones, you could cause riots with a well-timed, carefully planned tweet. Accuse Justin Bieber of fathering another child. Mention seeing someone suspicious sneaking into the Pentagon. Every RT increases the shelf-life of your tweet. It’s the endless cycle: if you tell two friends a secret, and they tell five people, and those five people tell five more people, then soon everyone knows your secret—or your tweet.