• by Wendy Davis , Staff Writer @wendyndavis, July 10, 2007

Nielsen//NetRatings said today it's going to start ranking sites based on how much time users spend at them, rather than how many page views they garner.

The move comes as Web publishers have upped their use of video; Ajax, which updates information on page without requiring users to reload; and streaming video, which also doesn't require people to navigate to separate pages. With the new time-based rankings, Nielsen joins the camp of those who've said for months that the new site designs require a ratings system based on something other than page views.

One result of the new methodology: video-rich sites will see a boost in ratings. Consider, MySpace attracts 10.4 times the number of page views as YouTube (around 28.7 million to 2.8 million), but users spend only 3.6 times as long on MySpace as YouTube (around 7.5 million minutes to 2.1 million minutes).

Meanwhile Google, which draws the biggest unique audience (110.2 million) ranks fifth in terms of minutes spent on the site (7.4 billion).

To some extent, however, these ratings aren't tied to ad dollars. Consider Google: while it might not keep people on the site for long, the company certainly has figured out how to make the most of that time by serving ads that users are willing to click on.