Mattress maker Serta has prevailed in its latest advertising dispute with Lexington-based Tempur-Pedic International.
At issue is which company's mattresses sleep cooler. The rivals took their disagreement to the National Advertising Division's self-regulation council, which is administered by the Council of Better Business Bureaus. The group investigates advertising claims between companies and rules on disputes. If its recommendation is not followed, the case is forwarded to the Federal Trade Commission for investigation.
Serta, based in Hoffman Estates, Ill., challenged Tempur-Pedic's claims that Tempur-Pedic mattresses sleep cooler than other mattresses and that its materials provide "unparalleled cushioning and support" compared to other memory foams, in particular Serta's gel-infused memory foam, according to an NAD statement.
Serta also challenged Tempur-Pedic's statements on its website and in commercials and signs that its foam is more durable than other foams.
In response, Tempur-Pedic cited testing by an independent lab that it commissioned. The testing suggested that Tempur-Pedic's mattresses are cooler over a seven-hour period.
The NAD noted that Tempur-Pedic "undertook a rigorous study to substantiate its advertising claims," but the NAD took issue with the claims made from the results.
Tempur-Pedic's commissioned testing took the temperature of a heated manikin test model sleeping on the mattresses. The case document said that the temperature of the manikin on Tempur-Pedic Contour and Cloud mattresses measured an average of 96.9 degrees, and it was 97.25 to 97.7 degrees on the four Serta iComfort mattresses tested.
The NAD said it was not convinced that "the results were statistically significant" based on the precision of the sensors used.
The investigators also questioned whether people would feel that degree of difference.
"The small differences in temperature between the results for both mattresses, all within the margin of precision of the sensors used in the study, has not been shown to be a consumer-relevant difference that verifiably feels 'cooler' to individuals lying on the various mattresses," the NAD said in its report.
In a statement published as part of the case, Tempur-Pedic wrote in response that the company thinks that "even slight temperature differences are relevant to consumers, and Serta provided no data to discredit this position."
The NAD recommended that Tempur-Pedic either modify or discontinue several phrases in the promotional materials.
Tempur-Pedic spokesman Mark Rupe said the company will follow the NAD's recommendation.
"The point of our 'cooler than the competition' claims was to refute erroneous claims being made by our competitors," Rupe said in a statement. "That campaign has been successful and has clearly established that no other memory foam sleeps cooler than Tempur-Pedic."
Serta spokeswoman Kelly Ellis said the company is "pleased with the decision" but declined to comment further "out of respect for the self-regulatory process."
The NAD's decision follows another made in January. In that decision, the organization agreed with Tempur-Pedic that Serta should discontinue or modify certain claims about the cooling benefits of its mattresses.
The cases began about the time Tempur-Pedic's rivals launched several competitive products in the memory foam mattress segment. It was a rocky 2012 for the company, which saw lower sales and profit than expected as the year went on.