• by Gavin O'Malley  @mp_gavin, Mark Walsh  @markfwal, July 11, 2007

In pursuit of accuracy, Nielsen//NetRatings has stopped ranking Web sites by page views and will instead rank them by time spent. In turn, Nielsen has recast the light shone on leading properties online.

The market research firm on Tuesday added both Total Minutes and Total Sessions metrics to NetView, its syndicated Internet audience measurement service. While NetView has always reported average time per person and average number of sessions, the new metrics are designed to better portray total engagement across sites.

"Total Minutes is the best engagement metric in this initial stage of Web 2.0 development, not only because it ensures fair measurement of Web sites using RIA and streaming media, but also of Web environments that have never been well-served by the page view, such as online gaming and Internet applications," said Scott Ross, director, product marketing for NetView.

As a result, industry watchers might see the digital world a bit differently. Take AOL: Ranked the sixth most popular site by page views, the Time Warner unit ranks first when measured by the time a user spends on a given page--largely thanks to AIM, its popular instant-messager service, which will now be counted in Nielsen's rankings.

Google, on the other hand, drops from third to fifth when Nielsen's focus shifts from page views to time spent.

The reason for Nielsen's move was attributed to the explosion in streaming video players and rich media application technologies like Ajax, which allow users to access content without fully reloading Web pages, thus making page views a less relevant metric.

"Page views have become a less reliable measurement because of all the Ajax technology being used now," said analyst Greg Sterling of Sterling Intelligence. "It's all about best reflecting engagement."

The new focus on time spent puts Yahoo in a generally better light--particularly when compared to Fox Interactive Media sites, including MySpace. That's because Yahoo incorporates Ajax technology in many of its most trafficked services, including mail and news, while MySpace still requires members to continuously reload pages to access new information and content. Yahoo beats FIM properties by less than a 10% margin in page views, but has more than twice the time spent.

Responding to industry pressure for more accurate measurement, Nielsen rival comScore Media Metrix recently introduced site "visits," or the number of times a person returns to a site with a break of at least a half-hour.

Agency executives welcomed Nielsen's move. "The page view was exposed as a flawed metric over the last year and Nielsen clearly listened to customers and tried to get out ahead of things with this new metric," said Jeff Lanctot, senior vice president for global media at Avenue A|Razorfish.

While supporting increased emphasis on the time-spent metric, Lanctot said digital media buyers will have to get used to relying on a variety of measurements, especially past campaign data. "I think what we've overlooked is the importance of third-party ad serving, because as you look over time what's most influential is the rich historical data that digital provides," he said.