Comcast should stop saying in advertisements that it “delivers the fastest Internet in America” and the “fastest in-home Wi-Fi," according to the advertising industry's self-regulation body. The evidence Comcast uses to substantiate those claims is not sufficient, ruled the National Advertising Review Board (NARB).

Verizon had challenged Comcast's advertising claims, leading to today's ruling. Comcast said today that it disagreed with the findings but will comply with the decision.

Comcast used crowdsourced speed test data from Ookla to make its claim about Xfinity Internet speeds.

"Ookla’s data showed only that Xfinity consumers who took advantage of the free tests offered on the Speedtest.net website subscribed to tiers of service with higher download speeds than Verizon FiOS consumers who took advantage of the tests," today's NARB announcement said. The Ookla data's accuracy wasn't questioned, but it was judged to be "not a good fit for an overall claim that an ISP delivers 'America’s fastest Internet.'"

The ad review board said Comcast's "America's Fastest Internet" claims gave the impression that Comcast offers "overall Internet speed superiority in all tiers of service that it provides." The Comcast ads also give the impression that Comcast "delivers the fastest download and upload speeds," whereas the Ookla data showed that the top 10 percent of Verizon FiOS customers had higher upload speeds than the top 10 percent of Comcast customers.

Comcast should feel free to accurately advertise the results of Ookla data as long as the company clearly communicates what the data represents, "avoids any statement or implication that the data demonstrates that Xfinity provides faster Internet speeds than competing ISPs," and distinguishes between download and upload speeds, the ad board said.

Comcast's "fastest in-home Wi-Fi" claim is based on router performance, even though Internet speeds are "primarily dictated by speed of the ISP’s Internet connection and dependent in large part on the Internet speed tier purchased by the consumer," the NARB said. "The panel found that Comcast did not provide a reasonable basis for the messages reasonably conveyed by the challenged 'fastest in-home Wi-Fi' claims and recommended Comcast discontinue the claims."

Comcast lost an initial ruling at the National Advertising Division (NAD) in this case in August 2016 but said it would appeal to NARB. Today's decision rejected Comcast's appeal.

Respectful disagreement

“Comcast agrees to comply with NARB’s decision," the company said in a statement. Comcast will apparently continue using Ookla data in ads.

"Comcast is gratified by NARB’s determination that Ookla’s crowdsourced data, which found that, based on 60 million speed test results, the top 10 percent of Comcast consumers had download speeds faster than the top 10 percent of Verizon FiOS consumers, can be used in Comcast’s advertising," the company said.

Comcast also said it disagrees with the finding that this evidence doesn't support its claim of "America’s Fastest Internet."

"Comcast also respectfully disagrees with NARB’s determination that the test results of its Wi-Fi gateway, found by NAD to demonstrate faster throughput speed at 5GHz, was not a good fit for the claim, 'Fastest In-home Wi-Fi,'" Comcast said. "Comcast will take NAD’s recommendations into account in developing future advertisements and expects NAD and NARB will hold all advertisers to the same standards when making similar claims.”

Comcast has also complained about Verizon's ads. In June 2016, the ad review board ruled that Verizon ads claiming that FiOS fiber service "is rated #1 in Internet speed" should be changed.

NAD and NARB are part of the advertising industry's system of self-regulation. Their decisions have no legal force, but the NAD says that "advertisers' willingness to support NAD and voluntarily adhere to its decisions helps to ensure an honest and open playing field in advertising."