Media research firm Nielsen/NetRatings said yesterday that it is emphasizing how long visitors spend at Web sites, rather than how many times they view a page, when comparing sites.
The move shakes up Web site popularity rankings, favoring sites such as AOL, Yahoo and others that attract heavy users of e-mail and instant messaging over sites such as Google and Fox Interactive Media's MySpace.
The new form of measurement won't change where advertisers put their dollars online, said analyst Debra Aho Williamson of Internet research firm EMarketer Inc. But it might change the way Web sites are structured. For example, some newspaper Web sites run stories across multiple pages to increase page views, but might have less incentive to do so under the new ranking system.
The two main Web measurement firms, Nielsen and ComScore Inc., are increasingly able to figure out exactly what people are looking at online, even when the page's content changes without having to hit the browser's refresh button. That means page views, once the industry standard, have become less important than other measurements.
"We're maturing with the industry," said Scott Ross, Nielsen/Net Ratings' director of product marketing.
Two recent major changes in Web publishing have led Nielsen to favor the time-spent measurement, Ross said.
First, technologies such as the software Ajax allow Web sites to show different parts of a page without refreshing the whole page.
The second shift that makes page views less relevant is the mainstream adoption of streaming video and audio, Ross said. A viewer sees the same page before and after pressing "play" on an online video - only the images in the video player change.
"We feel that minutes are better than page views for measuring the volume of usage on a site," Ross said.
With Nielsen's new measurement, Time Warner Inc.'s AOL rose to first place. Its users collectively spent 25 billion minutes on the AOL Media Network in May, largely because of the popularity of AOL Instant Messenger.
Alana Semuels writes for the Los Angeles Times.