Carriers are constantly touting the superiority of their networks in advertising claims in an effort to sway customers, but not all claims are equal. The National Advertising Division, an investigative unit of the advertising industry administered by the Council of Better Business Bureaus, has recommended T-Mobile discontinue claims that it has the fastest 4G LTE networks.

Verizon challenged T-Mobile’s advertising claims that it had a “faster” and “newer” network.

T-Mobile relied on crowd-sourced data from Ookla and Open Signal to support its “Fastest 4G LTE network” claim. However, after NAD’s review, in which the organization evaluated whether the data in support of the claim was consistent with consumers’ understanding of the statement, NAD sided with Verizon, saying the tests results might have had a bias favor of T-Mobile that did not support a comparative claim.

In its challenge, Verizon argued that users who participate in the Ookla and Open Signal tests represent a subset of all smartphone users that likely includes more sophisticated consumers. The carrier also said speeds recorded from Ookla may have slowed at the end of users’ monthly billing cycle when they were experiencing deproritization.

Since speed tests may have oversampled Verizon customers experiencing deprioritization, Verizon asserted that T-Mobile’s data may have misrepresented the comparative 4G LTE speeds most Verizon customers actually experience.   

NAD also recommended T-Mobile stop running ads that claim its network is “newer” than Verizon, because even though Verizon started building its network years before T-Mobile, both operators continue to invest in their networks to provide better service.

The organization also found that there was enough evidence to support T-Mobile running a modified ad about its network coverage. NAD concluded that T-Mobile can support its claim that it covers 99.7 percent as many Americans as Verizon, however it should remove imagery implying the carrier’s geographic coverage is nearly the same as Verizon’s.

Verizon said it was “pleased, though not surprised,” with NAD’s decision.

T-Mobile, in its advertiser’s statement said the company, “agrees to comply with NAD’s recommendations.”

However, Janice V. Kapner, SVP of corporate communications at T-Mobile said Verizon is “cherry picking” what was covered in the NAD decision.

In an emailed statment she said: “NAD ruled on one claim that we [T-Mobile] don’t even use anymore. Next. Verizon tried to refute our claim that we cover 99.7 percent as many people as they do. We substantiated it and NAD agreed. Win for T-Mobile. On the fastest LET newtork challenge, NAD ruled that the one month of crowd-sourced data we submitted (when Verizon launched their unlimited plan) could not be used. NAD previously recognized third-party crowd-sourced data as a way to look at network performance, so we looked at the latest reults, and verified what we already knew! T-Mobile is still the fastest LTE network and we’ll continue to let consumers know that!”

For a deeper dive into various newtork testing methods, be sure to check out tomorrow’s episode of Tuesday’s with Roger on Wireless Week.