Charlotte McKinney was featured in a Carl Jr burger ad, wearing a tiny bikini, but sex isn't selling, accord to a new study. (Photo: ScreenCap)

Charlotte McKinney was featured in a Carl Jr burger ad, wearing a tiny bikini, but sex isn’t selling, accord to a new study. (Photo: ScreenCap)

Charlotte McKinney and Kate Upton in skimpy bikinis chowing down on fat Carl’s Jr. burgers may draw a lot of gawkers on social media, but the commercials aren’t selling more burgers, according to a new study.

The controversial ad featuring McKinney, who appears nude but is actually wearing a string bikini, aired during this year’s Super Bowl.

While 27 percent of the people who saw the ads said they planned to visit a Carl’s Jr. or Hardee’s after watching it, the response was well below normal, according to Ameritest, a leading ad testing agency.

In response to typical burger ad–without the T&A–some 43 percent of those surveyed, on average, said they would go to the restaurant after watching, Ameritest’s Sean Scott told Ad Age.

While it may not be selling more burgers, Carl’s Jr. is definitely raising its profile on social media. The ad featuring McKinney, who replaced Upton this year, has been viewed more than 10 million times on YouTube. She debuted for Carl’s during the Super Bowl.

Nearly everyone (94 percent) of the people who saw the ad made the connection between McKinney and Carl’s, according to the survey.

And no wonder.

Thanks to well-placed fruits and vegetables, (honest) McKinney appears to be naked as she walks through a farmer’s market. She’s actually wearing a bikini, though it couldn’t get much smaller.

What looms large in the commercial is a big, fat, greasy Carl’s Jr. burger, which. the ad notes, is “all natural.” Yes, that’s a double entendre aimed at the model’s copious breasts.

The ad also produced some backlash. Just over half of those who saw it (52 percent) found the ad offensive and 51 percent found it “irritating and annoying,” the survey found.

Incidentally, the burger contains grass-fed beef without steroids or other additives topped with cheese and tomato.

The double is a “1,400-calorie monster,” according to USAToday. That’s almost the entire recommended caloric intake for a day, according to the Food and Drug Administration.

A rep for CKE Restaurants, which owns the brands, told Ad Age the findings were inconsistent with its internal research. It showed sales hitting a high during Super Bowl week.

What the rep failed to mention is the $1-Off coupon included with print ads, countered Scott.

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