n drove innovation and resulted in the build-out of high-speed fiber-optic networks. Large incumbents responded with their own network improvements and lowered prices. A similar pattern occurred in cellular networks after 1999. In the years since 1997, most small and medium-sized and even some large competitors were either acquired by large incumbents or went out of business. These incumbents also acquired other large providers that were formerly part of the Bell system. The result of these mergers is that today' telecommunications, cellular, and cable TV markets have far fewer competitors: mainly AT&T, CenturyLink, Comcast, and Verizon. Partly as a result of minimum competition, prices for broadband services are higher compared with most of the world. Social networking, cloud, and Office software conglomerates Amazon, Facebook, and Microsoft have built large, cloud-located networks of data centers. Their services have disrupted commerce in each of their fields. Microsoft operates one of the four largest cloud services in the United States. It offers a platform on which developers customize Microsoft applications for enterprise customers. Additionally, their Teams service is used by enterprises to make low-cost international www.TechnicalPDF.com voice calls and video conference calls and collaborate on joint projects. Google, which was started by Stanford graduate students, operates the largest search service in the United States. The founders used software to search the web and keep repositories of web site addresses. It quickly became an enormous company, whose popularity grew through word of mouth. They are now a huge conglomerate that earns billions of dollars each year through the advertising on their site. Amazon was started by Jeff Bezos. Its cloud-based retail service is another example of a business that has had an enormous impact. Brick and mortar retailers have lost millions of dollars, chains have gone out of business, and many have closed a number of their stores. Amazon is still innovating with its 