According to new, daily tracking statistics from YouGov's BrandIndex, Apple dropped from a peak score of 48.1 in the month of November to a score of 22 last week. That took it below Motorola, which remained relatively static from its month-long peak of 32.3, finishing last week with a score of 29.3.
The study's scale ranges from -100 to 100, based on interviews conducted with 5,000 people each weekday from a representative U.S. population sample. YouGov conducts more than 1.2 million interviews per year, selected from an online panel of more than 1.5 million unique individuals. The study has a margin of error of +/- 2 percent.
The company said its survey demonstrates that Motorola has likely come out on top of the ongoing advertising dispute between Verizon and AT&T.
"Motorola has seen its brand loyalty unaffected by AT&T's lawsuits against Verizon Wireless and ad war bashing," YouGov said. "But it seems to have taken a toll on Blackberry, which has withered under all the Droid/iPhone marketing and hype."
This week, Apple indirectly joined the dispute with two new ads that tout features available only on AT&T's UMTS/GSM network. The advertisements debuted after the most recent study results from YouGov were released; any potential impact from the ads likely wouldn't be seen for weeks.
It's a similar story to earlier this month, when Verizon's brand perception soared while AT&T sunk in the 18- to 34-year-old target demographic. The study suggested that Verizon and Motorola's advertising campaign for the Droid, which launched on Oct. 18, proved effective. Those ads, along with network-specific TV spots from Verizon, directly targeted both Apple's iPhone and AT&T's coverage.