The National Advertising Division (NAD) recently recommended that Dyson, Inc. discontinue certain superior performance claims for its DC65 and DC59 vacuum cleaners that NAD found lacked adequate substantiation. To support its claims, Dyson had conducted six separate performance tests of its vacuums and 61 competitor vacuums on a variety of different floor surfaces, and then aggregated the performance scores into a geometric average to arrive at an overall performance score. Dyson submitted that its DC65 vacuum achieved the highest six-surface “geomean,” and that an independent lab separately tested four of the top-performing competitors to confirm this conclusion. Thus, the advertiser contended it had established the DC65’s overall superior performance. The NAD noted that, under certain circumstances, aggregating scores is appropriate and called for by industry standard tests in this area. Even so, the NAD concluded that the evidence did not support a broad “superior cleaning on all surfaces” message and recommended that the claim be discontinued. In particular, the NAD noted that a claim based on aggregated results should communicate an aggregated performance message – instead, Dyson’s claims conveyed that the DC65 performs best on all floor types, and its disclosure naming the specific ASTM tests used was unclear, inconspicuous, and insufficient to cure the problem. The NAD similarly recommended that comparative performance claims regarding suction be modified or discontinued, also based on a lack of adequate substantiation across all surfaces (including carpet).

Tip: Advertisers are responsible for all messages reasonably conveyed in their advertising, not just intended messages. Comparative superiority claims based on aggregated data from different types of testing challenges should be clearly communicated as such so as to avoid communicating superiority for each specific type of challenge.