A smile can be a predictor of a marketing campaign's success.

Photo: Shutterstock

Part the complexity of marketing comes from the fact that multiple small factors can dramatically influence consumer behavior. In fact, a recent study from the University of Kansas shows that something as seemingly irrelevant as the size of someone’s smile can actually has a huge influence on how consumers perceive the marketer.

“We found that broad smiles lead people to be perceived as warmer but less competent,” said study co-author Jessica Li, a marketing professor at the University of Kansas. “We ask how that can influence consumer behavior and in what situations might marketers want to smile more broadly.”

According to the study results, context is key.

When respondents were looking at an ad for something deemed risky, such as a medical procedure, legal representation, or an opportunity to invest in a startup, slight smiles won out. This is because the smile made the doctor, lawyer, or businessperson look friendly but still competent. On the other hand, people who smiled more broadly were seen as less competent, so respondents were less inclined to work with them.

To build on their findings, researchers analyzed a number of Kickstarter campaigns. It turned out that when the campaign creator’s photo exhibited a broad smile, the total pledges decreased by more than 50 percent over campaigns where the creator’s photo showed a slight smile. Not only that, but the average contribution per backer was 30 percent less for campaigns where the creator smiled broadly in their photo.

“Project creators with a slight smile are perceived as more competent,” Li said. “People wanted to donate more to their project because they believe this competent person is able to deliver the product.”

On the other hand, broader smiles tend to elicit more responses for low-cost or low-risk activities. Photos with broader smiles tend to bring more customers into stores and cafes, for example, and they also get more likes and shares on social media.

Marketers can use this study to strategize on how to get the best responses for their campaigns, noting that slight smiles would be more effective for high-cost, high-risk investments and broad smiles will bring more customers in the door of a retail outlet.

“Warmth and competence are such important judgments,” Li said. “We want to make sure we are giving people the right signal.”