Vacuum rival Dyson claims company’s “preference” tags are full of hot air
The Competition Bristles
SharkNinja, manufacturer of the Shark Rotator Powered Lift-Away vacuum, made some strong claims regarding the popularity of its product. In television ads and online, the company boasted that “America preferred … Shark” and that “two out of three” people preferred their vacuum over Dyson’s Cinetic vacuum. Dyson challenged the claims before the National Advertising Division (NAD), which launched a self-regulatory proceeding.
At the heart of Shark’s preference claims was a national in-home use test that the company commissioned using third-party experts. Shark maintained that its performance claims “were supported by the results of [this] double-blind, multi-week, head-to-head, paired-preference study of 355 subjects at eight centers across the United States.” Shark reported that it had provided each subject with new vacuums, one Shark model and one Dyson model each. The subjects were asked to use both vacuums for two weeks in their “household routines” and “in all of the ways (and for all of the tasks) that you would use a vacuum that you owned.”
When NAD reviewed the methodology of the study, it was left with concerns that were hard to shake. NAD questioned the study’s length, deeming the two-week period to be too short to produce meaningful results. More important to NAD, though, was the nature of the test itself. NAD found that there was no clear direction as to how and under what conditions the vacuums should be used in the test. It also faulted a lack of follow-up questions to document the actual usage of the vacuums by each subject.
The NAD decision provides guidance regarding the care that advertisers need to take when commissioning studies that measure consumer preference. Companies that want to make comparative claims need to ensure that their experts use methodologies that make meaningful, well-defined comparisons. Shark has agreed to comply with NAD’s recommendation that both claims be discontinued.