Five San Francisco bus shelters were equipped on Monday with ads embedded with the scent of cookies, according Louis Zafonte, spokesman for New York-based Arcade Marketing, which designed the ads.
The campaign was launched by the California Milk Processor Board.
"Scent is a primary driver of memory," Zafonte said. "When you smell baby powder or chocolate chip cookies, everyone feels good."
To overcome the frequent blasts of exhaust and the funky whiffs that often permeate a big-city bus shelter, scented oils were sandwiched between cardboard cards emblazoned with "Got Milk?" and affixed to shelter walls.
It costs about $30 per shelter, Zafonte said, and the smell should last one to two weeks depending on the location. The displays will last about a month.
There is nothing new about scent marketing — using smell to sell. Trying to lead people by the nose subliminally is a growing advertising technique, reports CBS News correspondent John Blackstone.
Critics have complained the ads could be offensive to the poor and homeless who cannot afford to buy sweet treats.
But shoppers near San Francisco's Union Square shelter simply thought the ads were cute.
Nick Fedoroff, 32, said the smell might improve business at the Mrs. Fields cookie store a few steps away from the bus stop.
"I'm sure they'll be happy," he said. "It smells like they're right out of the oven."