There are big changes underway over at MSN Video, some of which represent a real look forward for the industry. It's hard to believe, and it isn't pretty, but this is a site you've got to check out. The site's design, full screen player and advertising model are big.

Time on Site

The big news at MSN Video is that the site has embraced a "Time on Site" traffic metric that's sure to represent the future of advertising. Neilsen announced this summer that they are replacing page views with time on site as the primary web traffic metric. It's widely acknowledged that AJAX and online video are making pageviews less and less relevant all the time. While other sites (like YouTube and MySpace) keep pumping out the pageviews and trying to figure out how to best run ads - this new MSN Video site has hit on a formula that will likely represent the video portal of the future: AJAX powered video playlists, including recommended videos, that do not require new pageloads and are monetized by time-based advertising. You could spend hours watching a playlist of videos from a variety of sources on MSN Video without ever loading a new page.

There's a really nice multi-video full-screen player, too. Viewers can even edit their playlists from inside the full-screen view. As an interesting aside, reader Mike Kowalchik notes in comments here that the video is all in Adobe's Flash, not Microsoft's new SilverLight format.

How the Ads Work

Visitors to MSN Video now see a pre-roll ad before their playlist of videos and then are shown another ad at most once every 3 minutes, regardless of the number of videos they have watched. It's much better than standard pre-rolls and sure to be more effective than post-roll ads.

The fact that the pre-rolls are unskippable needs to change, and 3 minutes still seems awfully frequent for ads - but the point is that this is advertising no longer tied to pageviews. You can't currently embed live players off-site, the site's aesthetics are MSN-ugly, and MSN itself is supposed to be a deprecated brand in favor of Live.com . Regardless of all that, check out the new MSN Video. It represents the future of these increasingly important types of sites.