Portal Kombat: the battle between Web pages to become the point at entry to the World Wide Web

Over the past few years the Web has grown to several hundred million pages, while just a few of them get most of the visits. Such sites, called portals, attract visitors, advertisers and provide lots of valuable content at no charge to the visitors. The portals attract disproportionate amount of the Internet advertising dollars and have the ability to influence the success of new electronic commerce ventures. In this paper we show the evolution of portals from a Web in which all pages are equally accessible. In addition, we analyze the nature of the competition between portals and show the impact of technological developments and added services on their economic viability.