In 2007, researchers led college students into a computer lab and asked them to read a web article about online education. The students were told that, once finished, they would be asked about the article. But what the researchers really wanted to know was how the students felt about the advertisements displayed above it.

As students read, random banner ads rotated above the article every five seconds. One group of students was occasionally served an ad promoting a digital camera from a made-up brand. A second group (the control group) never received it.

Later, when students were asked to evaluate some of the ads, the students from the first group rated the digital camera ad much more favorably than the students from the control group. Neither group recalled having seen the ad before.

The phenomenon at work here is the mere exposure effect. The above experiment is just one of hundreds — ever since Robert Zajonc’s landmark 1968 study popularized the mere exposure effect — that supports it.

What Is the Mere Exposure Effect?

A phenomenon causing people to like something more as a result of previous exposure to it, however brief and fleeting.

To be “merely exposed” to an object, a person has to at least perceive it. Their attention is usually aimed elsewhere though — like the students in the above experiment who noticed the ads, but didn’t really focus on them, because they were reading.

Anthony Grimes, a senior lecturer in marketing at the University of Sheffield who wrote his doctoral thesis on the mere exposure effect, told Built In there’s still value for brands when their ads get noticed, even if the noticing is brief.

“These fleeting, repeated encounters can nonetheless create a warmth toward the brands,” Grimes said, which is “factored into consumer judgments and behavior down the line.”

Grimes, and other researchers of the mere exposure effect, have observed several implications the phenomenon has for marketers looking to reach audiences in a cluttered digital environment.

ReadWhat Makes an Ad Effective?


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Image: Twenty20Photos / Envato Elements

It’s About Repeated Exposures

While a brief single exposure to an ad is enough to get someone to view it more favorably, studies reveal that repeated exposures are even more effective, Grimes said.

Even if you don’t click on the sneaker ad that’s been following you around the internet all week, the fact that you’ve had repeated encounters with it — even if you register it only cursorily — means you’re more likely to reach for it than its competitors on equal footing.

While this repeated exposure effect finds an obvious application in online retargeting efforts, marketers can also keep it in mind as they create integrated campaigns across multiple channels by using consistent visuals and messaging.

Every impression, no matter how fleeting, can help increase favor.


It’s Not Subliminal Messages

While researchers have found that the mere exposure effect works even if people don’t consciously remember having seen the target stimuli before, this doesn’t mean marketers should try to sneakily pepper audiences with subliminal messages.

According to Grimes, marketers may want to think twice before trying to pull a fast one.

“There is evidence to suggest that, where audiences pay enough attention to these to at least remember having seen them before, the effect can be slightly stronger; so this is not about hiding messages or presenting them subliminally,” he said. “That is an important point, not only from an effectiveness perspective, but also from an ethical one.”


Ads Work Even When People Don’t Click

It’s natural to doubt the impact of marketing activities whose primary aim is to generate brand awareness. After all, you can’t measure that as easily as clicks or other performance metrics.

But what the mere exposure effect suggests is that marketers might be placing too much emphasis on click-through rates.

The researchers behind the college student banner ad experiment suggested as much: “Even when there is no overt sign of effectiveness, such as recognition or click through, the banner ads may still impact ad liking,” they wrote.

Grimes agrees: “Your advertising can still be working for you in subtly positive ways, even when traditional metrics ... might suggest otherwise.”

While marketers shouldn’t stop trying to optimize click-through rates for digital ads, they can trust that top-of-funnel campaigns designed to generate flyby impressions, rather than conversions, are still effective.

They just may not pay off until later down the road.


There’s No Such Thing as Overdoing It ...

An old adage says that familiarity breeds contempt. But mere exposure effect research suggests that isn’t always the case.

Among the findings of the banner ad study is the suggestion that “consumers tend to have a relatively high level of tolerance for repeated exposure to banner ads,” the researchers wrote. “The wear-out effects of banner ads did not kick in even after 20 exposures in this experiment.”

In other words, the students never showed signs of getting sick of seeing the same ads.

So if marketers are worried about overexposure — they really needn’t be.


... but That Doesn’t Give Marketers Permission to Be Boring

Angela Lee, a professor of marketing at Northwestern University’s Kellogg School of Management who specializes in consumer psychology, said repeated mere exposure to an object doesn’t always and infinitely result in an enhanced liking for it.

There is a point, she said, where the mere exposure effect can hit diminishing returns — backfire, even. It’s when the stimulus gets stale.

“Sometimes it plateaus and comes back down,” she told Built In. “And that is caused by boredom.”

If audiences keep seeing the same exact image or slogan over and over again, they will eventually get bored.

“You repeat the same concept, but in a very different operationalization.”

The trick is to stay exciting, by making subsequent ads slightly different and more complex, Lee said.

“You repeat the same concept, but in a very different operationalization. ... If it’s complex, it takes longer for people to get bored.”

Is there a magic number of exposures marketers can make sure they never cross? Just to be safe?

“Identifying an optimum number of exposures is likely too difficult,” Grimes explained. “So long as participants are not exposed to them in a very boring, monotonous way, they are likely to remain effective.”


Ambient Marketing Capitalizes on the Mere Exposure Effect

Marketing that engages audiences and forces them to pay attention and process the brand or product are, in most cases, likely to be more effective than the brief, hurried ad encounters, Grimes said. So marketers shouldn’t ditch the former in order to focus on the latter.

Instead, they should consider marketing activities that reach audiences at both high and low levels of attention.

Common marketing activities that demand relatively higher levels of attention include case studies, blog posts, white papers and product demos.

Ones geared toward low levels of attention could take the form of banner and native ads, out-of-home advertising like billboards and benches, as well as television commercials.

In Grimes’ view, it’s important for marketers to make sure audiences in these environments can still recall if they’ve had previous exposure to the brand or product. So consistent, cohesive copy and design — not subliminal messaging — is key.


Mere Exposure Is a Tiebreaker, Not a Kingmaker

The effects of mere exposure are subtle.

“You are not going to turn brand hate into brand love by mere exposure alone,” Grimes said.

However, if consumers have to choose between two brands, each with comparable brand equity, mere exposure to one might “tip the balance from 50/50 to 55/45 (maybe even 60/40) in its favor,” he added.

A possible explanation for this is that humans are risk averse: New means dangerous, familiar means safe. So reaching for the brand they have had some prior exposure to feels like less of a gamble.

While mere exposure to one brand won’t necessarily peel consumers away from the industry leader they’ve been buying from for years, it can help the brand separate itself from the pack. And over several years, on a global scale, those tiebreakers can add up.

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