Simplicity has played an important role in Twitter's success.
People are eager to connect with other people and Twitter makes that simple.
Twitter asks one question, "What's happening?" Answers must be under 140 characters in length and can be sent via mobile texting, instant message, or the web.
In countries all around the world, people follow the sources most relevant to them and access information via Twitter as it happens—from breaking world news to updates from friends.