It's a highly effective way of spreading ideas, information and content. Don't be distracted by the 140-character limit. A lot of the best tweets are links. It's instantaneous. Its reach can be immensely far and wide. Why does this matter? Because we do distribution too. We're now competing with a medium that can do many things incomparably faster than we can. It's back to the battle between scribes and movable type. That matters in journalistic terms. And, if you're trying to charge for content, it matters in business terms. The life expectancy of much exclusive information can now be measured in minutes, if not in seconds.
Alan Rusbridger (2010) "Why Twitter matters for media organisations" theguardian.com, Friday 19 November 2010. As cited in: Megan Knight, Clare Cook (2013) Social Media for Journalists: Principles and Practice. p. 77.