The Associated Press reports that the Nielsen measurement service will change the way it tracks online viewing habits.

Although Nielsen already measures average time spent and average number of sessions of each visitor to a site, it will start reporting total time spent and sessions for all visitors to give advertisers, investors and analysts a broader picture of what sites are most popular.

There are several interesting implications in this decision.

As the AP notes, current metrics are focused on page views. However, certain websites are:

increasingly using a software trick called Ajax that allows sites to update data automatically and continually, without users needing to pull up new pages. Page views decline as a result. Page views also drop as people spend more time watching online video at sites like YouTube, owned by Google.

What does it all mean? Well, it's a difficult question to answer. Gawker Media still follows the page view model—at least in terms of measuring the efficacy of its employees and health of its websites—and we're wondering whether the switch by one of the leading online statistical analysis teams will somehow result in a change of policy geared more toward duration of readership rather than simple eyeball-counting might somehow convince our employers to alter the way they track what we do.

Under the current model, success is fairly easy to calculate. A post about, say, an Amy Winehouse sex tape, is guaranteed to do decent numbers. Merely mentioning the name Paris Hilton, or Britney Spears, or, say, one of the harlots from "Laguna Beach" results in some fairly helpful hits from Google searches, particularly if those names are placed in close proximity to the word "naked" or some variation thereof. If a post contains a phrase like "Dita Von Teese totally nude" it's probably going to do well. But it's not that simple: something like "Rupert Murdoch sex orgy" isn't going to get many hits. We hope.

However, if we start being rated on duration, the game changes completely. No longer will it be enough to suggest that there's a video of Vanessa Minnillo giving Nick Lachey a blowjob. We'll have to keep you at your computer, reading the entire post while we describe the Vanessa Minnillo blowjob. Does she rub Nick Lachey's balls while she's down there? Does she use teeth? Does he enjoy a happy ending? In this purely theoretical Vanessa Minnillo-Nick Lachey blowjob video story, we'll have to cover every angle of the oral sex performance which, while possibly titillating, will eventually grow tedious. Particularly for the writer, who may not have planned on spending his life writing text descriptions of celebrity oral sex.

And don't get us started on anal sex. Can you imagine what would happen if we ever got our hands on photos of Jessica Simpson and John Mayer engaging in anal? We would be here for days! We might even have to blog about it from our iPhone.

So the future is unclear. It's a difficult trick to keep people focused on one post, particularly if it's text-dense and lacking images of, for example, Angelina Jolie topless, bottomless, and totally shaved. We're not quite sure that we like where this trend is going.

Nevertheless, we will post on, bloggers against the current, borne back ceaselessly into photos of Madonna's ass. Or whatever the metrics show you're most interested in. It is our job, after all. By the way? If you've made it to the bottom here can you do us a favor and leave a quick estimate in the comments of how long it took you to read this? No reason, really, we're just curious.

Nielsen Revises Its Gauge of Web Page Rankings [AP]