Every grocery store knows that a hungry shopper is likely to buy
more. On the other side are product marketers who would love to stuff
customers with samples of specific items to obtain converts to their
brands. Retailers worry: Could food and product sampling sate
hunger—and with it, the desire to fill the grocery basket?

Baba Shiv, professor of marketing at the Stanford Graduate School of
Business, has found evidence that product sampling in fact can do what
a good French appetizer is intended to do: whet the appetite for
more—even in someone who was not hungry to begin with. Not only can
sampling stimulate the desire for more of the same product—cheese,
soda, or what have you—but it can also spark an overall desire for anything
pleasurable, be it other foodstuffs or even seemingly unrelated things,
such as exotic vacations and spa experiences. Such a phenomenon is
likely, then, to stimulate buying.

In a series of four studies, Shiv and colleagues Monica Wadhwa, a
doctoral candidate at the Business School, and Stephen Nowlis of
Arizona State University gave one group of students small samples of a
sweet drink or chocolate, and another group nothing, before having them
settle down to watch a film in a room with a selection of readily
available food or drink items.

Those who had been “cued” with the samples consistently ate and
drank more during the film than those who hadn’t. “We showed that the
intuition that sampling satisfies needs, and therefore decreases the
appetite for more, is wrong,” Shiv said.  “In fact, sampling stimulates
the desire for more.”

One study also indicated that presenting people with a good-tasting
sample may activate a general motivation for anything rewarding. Those
offered a sweet drink sample not only drank more soda during the film,
but also afterward indicated a stronger desire for a series of consumer
goods and experiences. The effect was the greatest for
pleasure-oriented items. Participants’ reported desire for more
decadent things like chocolate cake and a vacation in Bora Bora, for
example, was influenced by whether they had taken the sample drink.

Working off the hunch that brain chemistry might be at play, at the
start of this particular study Shiv and his colleagues rated people on
the behavior activation system (BAS) scale, a self-assessed measure of
one’s tendency to “go for what one wants.” “We hypothesized that people
with high BAS measurements were probably more prone to
pleasure-seeking, which has been found to correlate with activation in
the dopamine systems of the brain,” Shiv said.

Sure enough, test-subjects who scored higher on the BAS scale
consumed the most soda, led by those given the sweet drink sample
beforehand. When asked afterward to rate their desire for several
consumer products and experiences, these same participants also
recorded the highest overall ratings.

Could pleasant odors also activate people’s desire for rewards? Yes,
said the investigators. In a final study, they found that participants
who sniffed a good-smelling substance (scented spray) drank more soda
than those who sniffed a neutral-smelling substance (water)—and far
more than those who sniffed a bad-smelling compound (ammonia).
“Retailers who spray perfumes or have enticing food smells in their
store seem to know instinctively the value of scent in triggering
people’s pleasure seeking,” Shiv said.

One noteworthy finding was that once the whetted appetite is sated,
the effects of taste or odor samples don’t linger. The marketing
implication is that customers who taste a morsel of cheese may reward
themselves quickly by buying something luxurious, like a scented
candle, and be done with it––no overflowing grocery cart there.
Retailers, Shiv suggests, therefore may want to set up sample stations
at strategic locations within a store to keep stimulating in customers
the urge to indulge themselves.

Overall, however, the results of the studies suggest that stores
can’t go wrong by making samples available. An ounce of mango salsa may
turn out to be worth a pound of caviar.