Twitter, which began as a tool for sharing abbreviated blog posts, has now evolved into a major part of the news media. It may be the most significant advance in news since, if not linotype and the telegraph, then, at least, cable. As with cable, every new news event of consequence advances Twitter's presence and clout. It is first responder news; it is a real time news index; and, for more and more news consumers, it is background or passive news, like local radio once was, but on an international scale. Last week, Twitter announced another in a series of agreements with content providers, this time with Time Inc, Bloomberg, Discovery, Vevo, Vice Media, Condé Nast Entertainment and Warner Music Group, in a deal called Twitter Amplify that, only vaguely spelled out, joins publishers with advertisers under the Twitter umbrella. - Tom Himpe