• by Wendy Davis  @wendyndavis, July 23, 2015

The Better Business Bureau's National Advertising Division has told Euro-Pro to stop boasting that the Shark vacuum cleaner draws "more 5-star ratings online" than other brands.

"The individual sets of reviews relied upon by the advertiser (and consequently its analysis) lack important indicia of reliability and representativeness," the NAD writes in an opinion unveiled this week.

Euro-Pro intends to appeal to the BBB's National Advertising Review Board.

The self-regulatory group's opinion came in response to a challenge by rival vacuum cleaner manufacturer Dyson, which took issue with the methodology by which Euro-Pro concluded it has more 5-star reviews than its rivals.

Euro-Pro only considered online reviews that were "verified," which excluded ratings posted on the sites of four large retailers -- Target, Lowe's, Costco, and Bed Bath & Beyond. Euro-Pro also excluded online reviews posted at manufacturers' own sites. It also excluded reviews for vacuums that retailed for less than $149.99.

The sites that remained after the exclusions accounted for only around 39% of total online upright vacuum cleaner sales. That relatively small proportion wasn't sufficient to support Euro-Pro's "broad" boast, according to the NAD.

"The claim 'More 5-Star online ratings than any other vacuum brand' was a broad claim, reasonably conveying the message that Shark conducted an extensive, if not exhaustive, compilation of reliable and representative '5-Star' online-wide reviews in support of its claim," the NAD writes.

The group added that Euro-Pro's decision to summarily exclude all reviews from sites that do not specify whether users' posts are verified "sacrifices reliability because numerous sites that contain a hybrid of verified and unverified reviews are not counted at all," according to the NAD.

At the same time, the group acknowledged that including all online reviews in a calculation could also lead to unreliable conclusions.

"However, as much of a 'Catch-22' as this may be and as difficult as it is to parse out verifiable reviews, this does not relieve an advertiser from its obligation to provide appropriate and reliable substantiation for its advertising claims," the NAD wrote.

"Advertisers cannot base claims on tenuous evidence simply because sufficient reliable evidence is too difficult to collect."

Euro-Pro said it disagreed with the self-regulatory group. "The conclusion that a company like Shark cannot aggregate reviews across reputable retail platforms until there is some technical advancement that enables sorting out reviews one by one to determine which reviews are reliable does not recognize the savvy of the American consumer," the group said in a statement included in the NAD's opinion. "This decision also deprives consumers of meaningful information."

Dyson previously mounted a successful challenge to Euro-Pro ads that boasted Shark was the "most recommended" vacuum cleaner. In that case, the BBB's National Advertising Review Board said that online reviews didn't support Euro-Pro's claim that it was the most recommended brand, because many purchasers buy vacuum cleaners in person and don't leave online reviews.