Study: Four sites account for half of Web surfing

(CNN) -- Many thought Internet traffic would resist consolidation because of the seemingly infinite number of possible Web sites. They were wrong.

The number of companies controlling 50 percent of user minutes online in the United States shrank from 11 to four over the past two years, a drop of 64 percent, according a new report. The big four are America Online, Yahoo!, Microsoft and Napster. (AOL Time Warner is the parent company of CNN.com.)

Even more significantly, the number of companies controlling 60 percent of all U.S. surfing time plummeted from 110 to 14, according to Jupiter Media Metrix, which released the survey Monday.

"The data show an irrefutable trend toward online consolidation and indicate that the playing field is anything but even," said Jupiter analyst Aram Sinnreich.

The trend will likely continue, according to Sinnreich. The few businesses that dominate the market are directing traffic across their own network of sites, he said.

Web infrastructure now in place

In the past, putting together a Web site infrastructure was the primary hurdle for companies trying to muscle into the market. But that has shifted to advertising and marketing, Sinnreich explained, which favors giant media companies.

The rapid disappearance of small companies starved of investor cash has contributed to the consolidation, as has a flurry of mergers between corporate behemoths such as AOL and Time Warner, according to Jupiter.

The Internet heavyweights are mostly media and online portal properties. The most popular site devoted to e-commerce was eBay, which ranked sixth on the list.

Two-thirds of AOL Time Warner's minutes came from communications services such as e-mail and instant messaging.

The survey compared total home and work usage minutes between March 1999 and March 2001. Total usage minutes includes the time spent at a particular online property, Web site, category, channel or application.