Is Sprint as dependable as it claims?

Sprint (NYSE:S) has lost its appeal to the National Advertising Review Board panel, an advertising regulator that has disputed the third-largest U.S. carrier’s claim of being “America’s most dependable 3G network,” a claim touted by CEO Dan Hesse and on Sprint’s data-ridden commercials.

Verizon Wireless, which has spent most of its time going after AT&T’s network in its commercials, is actually the carrier responsible for taking Sprint to the regulators. In a press release issued today, NARB explained that Sprint’s claim was first challenged by Cellco Partnership doing business as VZW. The carrier approached the National Advertising Division of the Council of Better Business Bureau, which ultimately agreed that Sprint couldn’t back up its claim and recommended that it stop making it. Sprint appealed the decision to NARB, leading to today’s announcement.

Sprint said it could claim to be the most dependable based on Nielsen Mobile’s independent mobile data network performance benchmark tests that account for connection success rate, session reliability and signal strength in the U.S.’s 50 most populous cities. The average of two of Nielsen’s studies, done six months apart, put Sprint out on top. But NARB concluded that only the most recent test could determine the most dependable. VZW captured this title for both connection success and session reliability in the most recent study, conducted June 2008 to February 2009.

Sprint did, however, come out ahead in signal strength, but NARB ruled that it wasn’t enough to make it the "most dependable," nor were Sprint’s footnotes on its ads that indicated that testing time frame and signal strength were factors in the title.

“Consumers will reasonably interpret a ‘most dependable’ network claim as indicating the current status of the network, not its performance in tests that have been superseded by more recent tests, and thus the disclaimer contradicts rather than qualifies the main message of the advertisement,” the panel decision reads.

Sprint fired back in an advertiser’s statement that it “respectfully disagrees with the NARB's decision and maintains that its dependability claim was fully substantiated based on tests that were designed by industry experts to measure how consumers use 3G data networks.”

Even so, Sprint reportedly agreed to discontinue the claims and said it would take the NARB’s decision into account when developing future advertisements. It has already changed up its commercials to focus less on the network and more on its unlimited plans, 4G products and services.

This isn’t the first time Sprint’s claims have been called into question. Independent performance monitoring company Root Wireless found that Sprint had the highest connection fail rate in seven markets compared to AT&T, VZW and T-Mobile, but it also noted that it has the highest coverage network of the big four.