The ruling marked the first time that the NAD--the investigative arm of the ad industry's self-policing operation--considered claims of false advertising on video-sharing sites.

"This case establishes a precedent," Andrea Levine, the director of NAD, said in a statement e-mailed to MediaPost. "When an advertiser places a video on a site like YouTube and uses it, either to make claims about its own product or to compare its product to a competitor's product, those claims are advertising claims and, by law, require substantiation."

The case stemmed from an ad campaign for Dyson vacuum cleaners touting their allegedly superior ability to suction dirt without clogging. The campaign included a YouTube video that showed Dyson outperforming vacuums made by competitors. One Dyson rival featured in the video, Euro-Pro, complained to the NAD -- claiming that the ad was deceptive because the vacuums used in the test had different-sized receptacles, among other reasons.

Dyson pulled the video from YouTube, but the NAD still ruled on the issue. "Dyson's video depicted a comparative product demonstration and was therefore advertising and subject to the legal requirement that it be truthful and accurate," stated the opinion.

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