When high-calorie, nutrition-poor foods like Pop-Tarts, Doritos and soda were expensive, the shoppers purchased far fewer calories overall.

FORBES: Cheap Foods That Are Good For You

Factor in here that, in terms of being recalled by consumers, ads for branded drugs have trouble competing with, say, beer, soda pop, or even over-the-counter medicines, probably because what the drug companies can say is so heavily regulated by the Food and Drug Administration.

FORBES: Former Merck Exec Calls For Changes To Drug Advertising

The change follows a number of splashy moves in the past year by PepsiCo to improve results for its namesake soda, including a multiyear deal to sponsor the Super Bowl halftime show and a wide-ranging deal with pop star Beyonce.

WSJ: Pepsi rolls out a new shape for bottle

The product in question is Free, a soda pop celebrated in the commercial with images of gleeful guzzlers that include dancers and rockers, plus a blissed-out mime.

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