At the mall, in the supermarket, plastered on your subway car: It’s true, Taylor Swift (along with a number of other young and attractive celebrities) is indeed everywhere. A recent study may suggest a psychological reasoning for these stars omnipresence. According to the research, an image of a popular celebrity is bound to boost sales of not only their target product but also every product in proximity to the poster.

For a study now published in the Journal of Marketing Research, a collaborative team of researchers investigated just how much of an impact celebrity images had on consumer buying habits with a series of experiments. First, a poster of the widely popular Taylor Swift was placed near school supplies. Afterward, the poster was replaced with one of more controversial Miley Cyrus. The researchers then measured and compared products sales. Then, in a second experiment, the team ran a series of ads for a movie starring the favorable Will Smith as well as a series featuring the unfavorable Justin Bieber before a commercial for a fictitious shoe company. They then asked for the volunteers' opinions on the fictitious brand.

The results confirmed what the researchers had expected: Celebrity ads not only influenced attitudes toward the product they were advertising but also toward all products in visual proximity to the image. The presence of an unrelated positive or negative celebrity poster led to a respective increase or decrease in consumer spending on the school supplies, according to a press release. The results of the second experiment were consistent with these findings. Viewing the Will Smith movie ad led the participants to evaluate the shoe more positively, while the opposite occurred after viewing the Justin Bieber movie ad.

These results suggest that there is far more psychology involved in celebrity advertising than we originally believed.

"Marketers typically don't consider that the emotions produced in one marketing message may be influencing more than just our feelings toward the targeted product," the authors wrote. "Our study should encourage marketers to think about how the emotions we associate with one product may affect how we view the next product we encounter."

The findings could also influence the way in which marketers evaluate ad space; nearby advertising may be just as important as the ad's price and prominence when it comes to making a decision on where to buy space. “No matter how carefully designed, advertisements are not evaluated in isolation, and the emotions in one message can absolutely affect a neighboring product," the authors concluded.

Source: Hasford J, Hardesty DM, Kidwell K. More Than a Feeling: Emotional Contagion Effects in Persuasive Communication. American Marketing Association. 2015