Every technology era has its four horsemen driving growth and innovation. In the 1990s it was Microsoft, Intel, Cisco, and Dell. Today, there is anew "gang of four," as Google chairman Eric Schmidt puts it. They are Apple, Facebook, Amazon, and Google (of course), and they are behind the consumer revolution on the Internet today. Not only are all four companies "growing at incredible rates." Schmidt notes that all four are together worth about half a trillion dollars, they are all platforms in their own right, and they are all basically spreading their power where before there was only one company who had such influence: namely, Microsoft. But "Microsoft is not driving the consumer revolution," Schmidt notes (although they still do well in the enterprise).