When we talk about "gateways" to the Web, most of us tick off the names of four Internet companies: Google (GOOG), Yahoo! (YHOO), Microsoft (MSFT)'s MSN, and Time Warner (TWX)'s AOL. Collectively (with Google in the lead) they account for or broker 90% of the gross dollars advertisers spend online. And they get huge amounts of traffic, in part because millions of users choose one of these four as their home page. Each of the sites continues to draw well over 100 million monthly unique visitors.
But a shift is under way--one that is ushering in the next stage in the battle for influence on the Web. Other players are becoming gateways, too, in a kind of evolutionary advance that will change the way we use the Internet--and alter advertisers' behavior.
