MSN Video, which went live with an overhaul today, will limit its use of pre-roll video ads. In testing, the company realized that the frequent use of 30-second pre-roll ads was resulting in a negative user experience. The new system will serve up ads based on how long the user has been on the site, rather than the number of videos that have been viewed.  The decision will obviously reduce the site’s available ad inventory, at least initially, but letting the site go underused is clearly the bigger risk. NBC Universal (NYSE: GE) arrived at a similar conclusion earlier this summer, when it decided to can the use of 30-second pre-roll ads for its short online clips. Of course, pre-roll isn’t the only way to go for video advertising, as YouTube recently elected to go with ad overlays, which are seen by some as less disruptive. The new MSN Video will also incorporate content from its user-gen service Soapbox, which reopened in June after installing content filters. Release. (via MediaWeek)

SEE ALSO: YouTube Starts Overlaying Ads On Some Professional and User-Generated Video

—Lost Remote took a look at the pre-launch version.