Metrics drive marketing today. Every facet of the customer journey from awareness through conversion and into the loyalty building phase is tracked, analyzed, and scrutinized for competitive insights and key performance indicators.

Metrics come in the form of click-through and churn rates, incremental sales, web traffic, customer lifetime value, and countless others. However, one metric is a bit more difficult to assess and is hence too often left unexamined. Effective frequency is the number of times a person must be exposed to a message before it elicits a response of some kind.

How Many Exposures is Enough?

The guidelines surrounding effective frequency are more akin to rules of thumb than well established canons. This is possibly because every mix of brands, industries, and target markets has its own optimal messaging frequency, and thus universal solutions are invariably a poor fit.

The very first axiom on the subject, however, dates way back to 1885 in Thomas Smith’s pamphlet “Successful Advertising.” He described the reaction that is likely to occur the first twenty times a person is exposed to an advertisement.

In his view, the first time they look at an ad they don’t even see it. The second time, they see it, but don’t pay attention to it. The third time, they are finally aware of it. Smith didn’t think audiences even considered buying what the ad was selling until at least the fifteenth exposure, and wouldn’t make a purchase until the twentieth.

“People like to think that everything they think and do is the result of a conscious choice, a weighing of pros and cons, but much of our decision making is guided by silent, internal processes.”

Nearly a century later, Psychologist and consumer behavior expert Herbert Krugman reduced the analysis into three exposures during his time at General Electric. He called these phases: CuriosityRecognition, and Decision.

Krugman argued that the first exposure caused the viewer to ask: “What is it?” The second led them to wonder “What of it?” (i.e. does this ad or product have any personal relevance). The third exposure was the one that caused the message to connect and form a lasting memory.

Contemporary advertising theory provides an even simpler standard: a consumer must be exposed to an ad at least three times before they will be primed to make a purchase. Even a single exposure can influence purchasing intent and behavior, but like everything in marketing today, the rewards are great for those who do the hard work of analyzing and optimizing.

Avoiding Wear Out

Figuring out the right effective frequency is important for several reasons. Too few exposures and the message doesn’t connect and the viewer takes no action. Too many results in wastage, money spent repeating an ad that has already maximized its potential. Worse, excessive repetitions aren’t just a waste of resources, they might be actively turning potential customers off.

Effective frequency may be thought of as the cadence, or message repetition rate, necessary to cause a desired reaction, but its counterpart, acceptable frequency, is the highest cadence that won’t cause audiences to tune out or become annoyed.

For that reason, effective frequency is also known as wear in (because the message has to be driven home over time) and acceptable frequency is referred to as wear out (because too many repetitions begin to grate on audiences, undermining your efforts).

Wear out is one of the major reasons that brands commission several variations on a theme in an advertising campaign, rather than just endlessly duplicating a single message. Consistency is crucial to generating trust and building a brand, but consistent doesn’t have to mean monolithic:

“There are studies on the wear-out effect which show different ad themes have different thresholds of wear-out. To avoid wear-out, there should be variations of the ad so that the same message is reinforced without showing the same thing,” said Dr. Louisa Ha, professor of media production and studies at Bowling Green State University.

Hidden Influencers

A lot of research in human psychology underpins these theories of effective frequency. For example, the mere-exposure effect, also known as the familiarity principle, is a common phenomenon in which people gain favorable opinions about things merely because they are familiar with them. You might not like a particular ad with a groan-inducing pun or an unusual jingle the first time you hear it, but with repeated exposures, it’s likely to grow on you.

“A consumer must be exposed to an ad at least three times before they will be primed to make a purchase.”

People like to think that everything they think and do is the result of a conscious choice, a weighing of pros and cons, but in reality much of our decision making is guided by silent, internal processes. Purchases are often the result of an unconscious preference or association rather than a calculated choice.

Just like the mere-exposure effect is a psychological principle that encourages increasing advertising cadence, others provide a rationale for keeping it within a restricted range.

The concept of latent inhibition, for example, suggests that we are tuned to notice novel stimuli and will give less mental focus to things we’re already familiar with. It’s an evolutionary adaptation meant to protect us from dangerous unknowns, but in the context of advertising, it can help marketers avoid wear out.

Crunching the Numbers

Looking to generate some hard data to back up these theories, Facebook Marketing Science conducted a study of brand campaigns from January 2015 through February 2016 that found a causal relationship does in fact exist between brand lift and frequency level.

Source: Facebook Marketing Science

Their study indicated that ad recall rises precipitously as frequency increases and begins to fall after it reaches a cadence of one exposure per week. Purchase intent, however, didn’t begin to drop until it hit an average of one and a half exposures per week.

They concluded that while there isn’t a “magic frequency level” that will lift every brand, these figures provide a good starting point to direct targeting. They also advised that new and unfamiliar brands benefited from higher frequencies than established brands.

Other experts have suggested that high frequency campaigns are also well suited to low-involvement offerings like fast moving consumer goods. Big decisions require more planning and cost-benefit analysis, smaller ones less so, and hence are more influenced by heavy exposure and unconscious, embedded connections.

In another study, Oracle Data Cloud looked at campaigns that reached 60 million households. They found that for 80% of campaigns, the first impression made the biggest impact on incremental sales. But, just as importantly, subsequent impressions continued to generate positive incremental revenue.

Conclusion

In an industry awash in metrics, effective frequency is one that too many brands are failing to give enough attention to. Finding the sweet spot for your specific market and customer will lead to a more efficient and effective ad spend.