We have a lot of metrics available to us in the various platforms, ad managers, CPMs, clicks, reach.

One of the numbers marketers often keep an eye on is frequency. Frequency is a measure of how many times an average person in your target group has seen your ad.

There's great debate about what that number should be.

When I started my career in marketing almost 30 years ago, the going wisdom was that 27 was the magic number. Why? Because people thought it took nine exposures to an ad to make a decision, and that people only actually remember one out of every three ads. 9 x 3 was 27.

These days, of course, that number seems ludicrously high, and I think most people in our space believe that number should be between two and five, depending on what funnel stage you're at. Any more, and consumers become weary and start to get negative feelings about the ad.

There's been a lot of research on how much frequency is too much, but that research, to date, has focused on near-term results, more immediate effects, which is odd considering the whole point of marketing is to build a long-term relationship between the brand and the consumer.

Is it possible that if we push through the uncomfortably high frequency, yes, even if that generates short-term negative feelings that eventually, the consumer will warm up to the brand?

I recently interviewed Dr. Ann Kronrod — she and some colleagues have published an academic paper on this topic called How Time Can Reverse the Negative Effect of Frequent Advertising Repetition on Brand Preference.

Table of Contents

• The Three Factors
• What is the Magic Number?
• The Posters Test
• Impact on Purchase Intent
• The Mug Test
• When Would This Backfire?
• It's Counter to Everything We Knew
• A Novelty Discovery in Marketing Science?
• How Would Results be Different Today?
• Dr. Kronrod's Personal Interest

Tod Maffin: The main title of your paper was actually Ad Wearout Wearout. So ad fatigue itself eventually fatigues, is that right?

Dr. Kronrod: We're mainly talking about ad annoyance more than ad fatigue, but wearout combines together, I think, annoyance and fatigue.

Tod Maffin: You just said there's three factors, actually. Annoyance, memory, and brand preference. Can you walk us through each of those?

The Three Factors

Dr. Kronrod: Yes. In your introduction, you were actually mentioning that people might be very annoyed with ads, especially in the short-term. The question, what happens in the long-term, what happens with this annoyance and also with a parallel process, I guess, that is which is memory. These are two parallel processes that happen when you see an ad or whatever and both of them get higher the more times you repeat an ad. If you repeat an ad many times, someone would get more annoyed with it. That makes sense, but also, I was just saying, let's not forget, people will also remember it better.

The outcome of this is, “Okay, if I repeat the ad many times, then people get annoyed with it and remember it.” Well, is it good or bad for business? What we're trying to see and what we managed to see eventually in our field experiments that we ran on campus, but also in a more controlled lab experiment is that over time, there's an interesting thing that happens. Annoyance, which is a negative feeling, tends to fade much faster than memory.

You're over time. When I say over time, I mean about two to three weeks, which is not a lot of time, actually. Over time, you tend to forget that you were annoyed. The annoyance tends to go down, but memory actually keeps for a while, for a long while. It just keeps high at the same level for longer time, which is a very interesting thing. It's for any type. It's not only for advertising. It would be for any type of stimulus. We call it stimuli.

For faces or for people, you see them repeatedly and they keep annoying you, but then after a few years, you meet them, you forget that you were annoyed and actually, you remember them better. You're asking, “Wait, what about the preference?” That's the third. That's the outcome. If I'm measuring, and that's what happens a lot in marketing, as you mentioned, if I'm measuring the outcomes of ad repetition in terms of preference for a brand, if I do that immediately, I will see reduction in inbred preference because I'm repeating the ad too much and it's annoying, but then over time, this ad preference would be increased.

People would be more likely to prefer that brand for which the advertisements were more frequent, which is good news for marketers, of course.

What is the Magic Number?

Tod Maffin: Did you get a sense of where that tipping point is? Is it based on time, like after three months of heavy ad rotation or maybe impressions, like once you hit a frequency of 30, then things will eventually in the long-term turn around? Did you identify a numerical tipping point?

Dr. Kronrod: We did have an experiment that was over time. It didn't last for months. Actually, we didn't have to because what we saw is that– We had people exposed at the same time. If you're asking about how long should I keep the repetition going, this we had for technical reasons. We had to do that all at once. People were exposed to the same ads in our experiments within the same half an hour, which is very frequent, of course.

It was, in that sense, maybe less realistic, but then after that, they were not exposed to the ads so we can talk about the time lag between the exposure. I don't know how long it took and how many exposures you could play with that, and then the next time that you have to make a decision. There's something interesting that happens in between these two occasions. When you're exposed to some information, then you have to make a decision.

When you are exposed to the advertisement, that's not necessarily the time when you actually think about purchasing something, like wedding halls or venues. We're exposed to these advertising, but we don't consider getting married all the time. When time comes and this happens, it could happen years after you were exposed to that repeating advertisement for a particular venue. When time comes, that's when you actually form your attitudes about the venue.

At that time, it's really important that you are not annoyed anymore, according to our results, at least, but you remember this particular venue. It's really good news for marketers because it means that I can frequently repeat my advertisement and then I don't have to insist that people run and rush to purchase the product immediately. Actually, it would be in my benefit to wait.

Tod Maffin: I see. It's less about the specific timeframe and it's more about timing the offer. I'm thinking maybe a resort in Mexico where people are not shopping for resorts in Mexico in the heat of summer. Usually, they want to go in the winter. You maybe run all the repetition during that summer phase and then stop so that when they are in the winter, enough time has passed for the annoyance to wear off and the memory and brand preference to kick in. Is that more or less right?

Dr. Kronrod: Yes. I don't want to insist on the three weeks that I mentioned before of the time lag, just because the way I achieved these three weeks was experimental. It wasn't clean conditions. People didn't see any other advertisements during that time within the context of my experiments. It's not as realistic and therefore, I'm being cautious saying, “Oh, it's three weeks or three and a half weeks.” I don't want to do that, but that's the timeframe that I find in my experiments. We can start from that.

The Posters Test

Tod Maffin: I thought how you tested this in one of your experiments was both fascinating and a little funny, given that it involved hundreds of rubber spiders. Could you tell me about your testing methodology? Let's start with the posters.

Dr. Kronrod: First, this was for Halloween which is an American holiday. It is all about spooky stuff, right? We ran the experiment in university residence halls in dormitories where people actually decorate the rooms with different stuff and they have Halloween parties. Students, at least in the United States, they'd really love Halloween as a time to party. They use lots of spooky things. We bought a whole bunch of hundreds of those really small spiders as a decoration.

We kept them in a closed box so people don't know what we have for them, but before we sold– Or we didn't sell them. We actually gave them away for free, but before we did that, we advertised Halloween and the giveaway.

Tod Maffin: You did this through posters in the dorms.

Dr. Kronrod: Right. We designed two posters. It was indeed very much fun to design the posters, to think about the ad copy and all this stuff. As academics, we don't get to design ads that often, so I was really having fun being a copywriter myself. This was really fun. Why did we have more than one poster? Because one of the posters, we manipulated the number of repetitions and the number of times it would be on the wall by just leaving it on the wall for longer period so students that go by the board, they would see it over and over again every day and hopefully get annoyed by having it for so many days. We had to talk to the administration not to take it off.

Then in the other hole, we put another poster and we kept it for a lesser time online. We wanted to see if students would remember the poster and if students would prefer any of the two brands. We designed it as if the spiders were coming from two different brands. Eventually, we had people choose between the two brands and hoped– And actually, that's what we also saw when Halloween actually came and it was time to really make a decision.

Like I mentioned before, you form a decision, you form your attitude when it's time to do that, not when you see the ad. When they saw the ad, they remembered it and they were annoyed by it, both. The more frequently or the more days it was up, the more annoyed and the better they remembered it. Later, they forgot about the annoyance. The annoyance went down and they preferred to get the present from the ad, the brand that was represented in the more frequent ad.

Tod Maffin: Explain how that actually worked? Did you have a table set up with two boxes, one from brand A, one from brand B, and then they just had to pick which one?

Dr. Kronrod: That's exactly what we did. Yes. That's what we did. The interesting thing that happens is it has a name, but it doesn't matter, that over time, it's a survival mechanism. That over time, we tend to decay and put aside everything that is negative in our experiences and we just keep going with only the positive ones. That's how we explain why annoyance goes away so fast compared to memory.

Tod Maffin: Were they ever told that they had been part of an experiment with those posters?

Dr. Kronrod: Well, yes. If you're asking in terms of ethical conduct, if you run a field experiment and you need people to not know that they're in an experiment and behave naturally, one of the things that you often would do, it's called debriefing. You would tell them later when they're done, when you are done with them. You would tell them that, “Now, we're ready. Now, you have actually been part of an experiment. There's no risks to you and here's what happened. If you're interested to learn more, here's my email,” et cetera.

Impact on Purchase Intent

Tod Maffin: I guess one of the limitations of that approach though is that people were getting a free gift rather than making a purchase. Do you think the results would've been different if you'd have tested purchase intent?

Dr. Kronrod: Yes. This is definitely one of the limitations of anything that involves an experiment versus actually selling something. In academia, we're often limited because we can't have any financial interest. We are often not allowed to take money for anything and sometimes, experimenters even take money and then return it back to people if they're able. In our case, we weren't able to track back the students and get them back.

I wasn't testing people's ability or likelihood to part with cents or dollars. I was testing preference. This is just to remind that this was my dependent variable. This was what I was looking at and not so much about willingness to pay or would I buy it or not, but I agree with you that a nice extension of this research would be to actually try it with purchase.

The Mug Test

Tod Maffin: This rubber spiders thing was an in-person thing. I felt that your second test, well, the second experiment was a little closer to our world in terms of digital marketing. Can you talk about the travel mug ads?

Dr. Kronrod: Sure. This was the long-term experiment where people saw one of– They saw two ads. They were reading an article. Sometimes, when you read an online article, there are ads that pop up. I was trying to create this experience when you're reading an article online and some ads pop up and you can just get rid of them by clicking the X. It's not too much, but if they keep coming, then it's ad repetition. That happens from my perspective. That's what I wanted.

The ads for these two, just travel mugs, regular mugs that again, it was a little bit of fun for me because I designed the lousy ads for those mugs. The ads weren't very good because I'm not a very good copywriter, I guess. The ads were not amazing by themselves. That's a more, we would say more conservative test. The ads weren't that good. They were annoying by themselves, and then they also repeat during your reading of the article.

People kept reading the article. They didn't notice necessarily which ad appeared and when, which is also important because it's not a very conscious process. Then when they finished reading the article, we gave them a lag of time. Some people completed the next stage where they were saying which of the mugs they would prefer. Sorry. One of the ads repeated more often than the other. That was the difference between the two conditions, I guess, if you would say this way. Some people responded the next day. Some people responded after a week, two weeks, three weeks, and so on.

We were able to actually see a continuum, not just two spots. We were able to see a continuum of what happened to their annoyance towards the ads and compare the more frequent and less frequent one, and what happened to their memory of the ads. We were able to see not only preference, but also the why, why they preferred. This was a very nice explanation for what is going on. That annoyance goes down very sharply, but then memory sticks and keeps going for many weeks after you saw the ad.

When Would This Backfire?

Tod Maffin: Are there any instances where this play for long-term results, even though you are initially sacrificing a bit of negative sentiment against your brand, knowing that that will wear off, so that play for the long-term brand preference? Are there any instances where that would backfire?

Dr. Kronrod: I think when you make the mistake of trying to remind people, so you're trying to introduce or include elements from the ad, not only the product, but elements from the ad, like the jingle or the copy elements from the ad and you're reminding of the ad itself, that might be a mistake to do because at this point, you're reminding of the annoyance that was long forgotten.

Tod Maffin: Oh, I see. Because this is a short-term annoyance, you want to leave an actual real gap without any reminding.

Dr. Kronrod: Yes.

It's Counter to Everything We Knew

Tod Maffin: I'm pausing because it seems counter to everything we are taught in marketing, which is set up your offer and then every week or so or every day or every X period, constantly be in there. In fact, there are retargeting campaigns which are evergreen, which are on set it and forget it, where someone will spend time on a website or they will engage with the post and suddenly, they are in a bucket of people who are just going to see this ad constantly over the next X number of months. Whereas your research has found, “Actually, you should stop after a heavy cycle of repetition and let it marinate.”

Dr. Kronrod: Yes, I agree. I agree. In that sense, what I'm suggesting is different from the mainstream that would say, “Just keep advertising.” The main difference would be that I'm looking into the future, I'm saying, “Okay.” Frequency of repetition is something that has been explored in the short run. What would happen? In academia, people explore and they repeat the ads and immediately test what happens after that. Obviously, memory is great, but annoyance as well.

A Novelty Discovery in Marketing Science?

Tod Maffin: I don't know of any other study that studied or identified a long-term reversal of the effective ad repetition. Was this a new finding to the world of marketing science?

Dr. Kronrod: I hope so. Yes, but there was another paper that we referenced in our article that found something similar. I'm not sure I want to go into it. It's a little bit complex. There was one experiment that was actually a field experiment in I think it was a Super Bowl or some sports game. I'm sorry if I'm blanking on the exact sports game where they found that over time, ads that were repeated during the game, later, the more frequently they were repeated, people tend to purchase them. Over time, they tend to purchase them more. That's an actual marketing outcome, of course.

How Would Results be Different Today?

Tod Maffin: Your testing was done in 2017. Since then, ad platforms have matured. The products that they offer, in terms of the actual ad, products have gotten smarter, even entirely new platforms. TikTok have come along and dominated. Do you think there'd be a difference in your results if you were to test this today?

Dr. Kronrod: Yes. It depends what part of the change over time that we're looking at. For example, I think one change that has occurred is that ads today are more personalized due to the collection of data when you browse, so browsing data. If you're browsing and looking for, I don't know, handbags, suddenly on Facebook, you get ads on handbags. In that sense, since the ads are more relevant to you in the first place, now that they are personalized, there will be a reduction of the annoyance. I would expect it to be less annoying. Even if it repeats, you would feel that it's less annoying because it's relevant to you. All of this up to the point when you made the purchase.

Once you made the purchase, it's not relevant to you anymore, and now it gets annoying again.

Tod Maffin: Hopefully, people who are marketing, who are setting up those retargeting ads are excluding people who’ve purchased or maybe even putting them in a bucket, targeting for a different product like an upsell or something like that. ]

Dr. Kronrod's Personal Interest

Tod Maffin: What made you want to study this?

Dr. Kronrod: Well, it started actually from the relevance from the last point we just talked about. The earlier stages of this research were typically about relevance. I find the concept of relevance very interesting because I think it can move mountains, metaphorically speaking. It can change everything. For example, I've showed in previous research that has not got published in this article that if you advertise frequently about stuff that is relevant to people, they don't get as annoyed or actually, they don't even get annoyed at all. If you advertise about something that is not relevant, that's when you get to their bad side and you don't want to get there.