Steven Levy in Wired:
Last August, the people who putatively run Twitter — the small crew that three years ago launched the world’s fastest-growing communications medium — announced a relatively minor change in the way the site functions. The tweak would have a small effect on retweeting, the convention by which Twitter users repost someone else’s informative or amusing message to their own Twitter followers. Retweets start with RT, for “retweet,” and usually cite the first author by user ID. And, importantly, retweeters often add a word or two of commentary about the repeated content.
But there was a problem: Twitter itself didn’t invent retweeting; it was created by Twitter users. In a blog post explaining the changes to retweets, the company’s second-in-command, Biz Stone, called them “a great example of Twitter teaching us what it wants to be.” The good news, he said, was that Twitter was building retweets right into the site’s architecture. The bad news was that Project Retweet didn’t make any provision for the commentary that users might like to add.