Have you ever seen the same advert five or six times and thought, “Right, I am never buying that”? If so, you know exactly what Herbert E. Krugman warned us about over fifty years ago. His theory on advertising frequency changed the way marketers think about how often to show an advert. The core ideas behind it still hold up well today.[1][2]
I work with business owners on their marketing all the time. One thing I see again and again is that ad frequency is one of the least grasped parts of the whole game. Get it right and your message sticks. Get it wrong and you push people away. So let me walk you through what Krugman said, what the research tells us now, and what it means for your business.
Who Was Herbert E. Krugman?
Herbert E. Krugman was an American psychologist who spent most of his career at the General Electric Company. He served as manager of public opinion research there from 1967 until he retired in 1983. He got his PhD from Columbia University in 1952 and held roles at Yale, Princeton, and Columbia. He was past president of the American Association for Public Opinion Research and sat on the board of the Advertising Research Foundation.[3][4]
His biggest impact on our field came in 1972 when he published a paper called “Why Three Exposures May Be Enough” in the Journal of Advertising Research. In it, he set out a simple idea that shaped ad planning for decades.[1]
The Advertising Frequency Theory Explained
Krugman’s theory, often called the “three-hit theory,” says there are only three key levels of response when someone sees an advert.[2][5]
The first time, the viewer asks, “What is it?” This is pure curiosity. They have spotted something new.[6]
The second time, they think, “I have seen this before.” They start to weigh up whether the message matters to them.[7]
The third time acts as a prompt. The viewer either acts on the message or decides it is not for them. Krugman also said that this third viewing marks the start of mental switch-off. After this, the brain treats each repeat as just another version of that third response.[8][7]
In short, more than three viewings does not add new value. The viewer has made up their mind. Further repeats do not win them over; they just take up airtime.[6]
Did Other Researchers Back This Up?
They did, at least in part. In 1979, the Association of National Advertisers put out what is now known as the Naples Report, named after editor Michael Naples. This study pulled together the best research on ad frequency and found that three viewings within a buying cycle was a solid starting point.[9][10]
The report gave weight to what many ad people already felt in their gut. By some accounts, around ninety percent of packaged goods firms in the US built their media plans around it. The Advertising Research Foundation later broadened the view, saying most campaigns work best when people see the message between three and eight times. Below three, no one recalls it. Beyond eight, they start to tune out.[11][12]
Is There Such a Thing as Too Many Adverts?
Yes, and the proof is hard to ignore. A joint study by GWI and WARC found that 52% of people in the US and UK said seeing too many adverts was the single biggest thing that would put them off a brand. That was well above the 32% who said the same about adverts next to dodgy content. When asked to sum up the ads they see day to day, the word “excessive” came up time and again across TV, social media, and websites.[13][14][15]
Data from 2026 backs this up. Research by WifiTalents showed that click rates drop sharply after someone sees the same advert just four times. The cost per click jumps by 49% once the frequency hits nine. Nearly half of all web users, some 47%, now use ad blockers just to dodge repeat adverts.[16]
A study on ad fatigue from the IJRPR found that people shown high-frequency adverts had about 30% less interest in them than those who saw them fewer times. Adverts that felt pushy or off-topic led to real spikes in anger and annoyance.[17][18]
Advertising Frequency in the Modern World
Here is where it gets really rather interesting. A newer study in the Journal of Advertising Research by a team from the University of Tampa found that people may have a higher bar for ad repeats than Krugman or the Naples Report thought. Their data showed the best results at more than ten exposures, partly because the sheer flood of media we all face today has raised the bar for what we even notice.[19]
The authors noted that “media planners commonly adhere to past rules driven by dated research, planning for a frequency of between three and ten exposures.” They said that if the goal is to boost purchase intent, planners should aim for more than ten.[19]
Research from Sky Media in the UK found something similar. Across more than 100 campaigns, real wearout did not kick in until around 14 to 15 viewings. That is a long way from Krugman’s three.[20]
So does that mean you should bombard people? Not at all. It means the answer depends on the platform, the audience, and the quality of the creative work.
Do Adverts Really Wear Out?
This is where the debate gets really lively. System1, a UK research firm, looked at over 50,000 video adverts and found that ad scores did not drop over time in the way most marketers assumed. They tested 100 adverts four times over two years and saw no real fall in how well they worked. Some adverts, notably those with well-loved characters or catchy slogans, scored better as time went on. System1 calls this “wear-in” rather than wear out.[21][22]
Jon Evans, chief customer officer at System1, put it well: “The myth of wear out in ads has a hidden cost. Good ads are cut down in their prime when they still have so much to offer.”[23]
A smart study from Duke University by Dr Ann Kronrod and Professor Joel Huber added a twist. Yes, seeing the same advert a lot does raise annoyance in the short run, but it also boosts memory. The clever bit? Annoyance fades much faster than memory does. After about two to three weeks, people had mostly lost the feeling of being annoyed, but they still recalled the brand. When asked to choose, they picked the brand they had seen more often.[24][25]
What About the Long Game?
Dr Kronrod’s work hints at something that runs counter to the usual marketing playbook. Rather than keeping up steady ad pressure at all times, there may be real value in running a burst of ads and then leaving a gap. In that pause, the annoyance melts away while the memory stays strong. The net result is a win for the brand when the buyer finally makes a choice.[25]
What Does This Mean for Your Business?
If you run adverts for your business, the lesson from all this research is pretty clear. You need at least three exposures to make any mark at all. Below that, you are invisible.[11]
The sweet spot for most firms sits between three and seven exposures per campaign run. That is where recall is strong, action is likely, and your budget does its best work. Once you go past eight to ten views with the same creative, the returns start to shrink. People tune out, or worse, they start to feel cross with your brand.[11]
Here are some steps worth taking. Check your frequency scores on Meta and Google Ads each week. If your click rate drops while your costs rise and frequency climbs, it is time to refresh your creative or widen your audience. Aim to swap out your ad creative every two to three weeks; studies show this can lift click rates by up to 30%. Use frequency caps on digital platforms, and three views per day per person is a good rule of thumb.[16]
The quality of your creative also plays a huge role. A strong advert can handle higher frequency before people start to glaze over. As System1 showed, adverts with great characters and catchy hooks can actually get better with more airtime.[26]
The Lesson for Advertisers
Herbert Krugman’s advertising frequency theory has been tested and refined over more than fifty years. His core point, that repeats reach a level where they stop helping and start hurting, has stood up to decades of further study. The exact number shifts based on your channel, your audience, and the quality of your creative, but the rule of thumb holds.[19][11]
In my work with business owners, the biggest error is not showing adverts too often. It is running the same stale creative for too long without a refresh. Keep the message steady, but keep the look and feel fresh. That is how you stay in the zone where Krugman’s theory works in your favour.
References and Further Reading
[1] Herbert Krugman, “Why Three Exposures May Be Enough,” Journal … https://ptgmedia.pearsoncmg.com/images/chap04_0321733010/elementLinks/fn10.html
[2] Stop Guessing: The Proven Frequency That Makes Ads Work https://www.gowithbigtime.com/blog/C/2025/09/24/Stop-Guessing-The-Proven-Frequency-That-Makes-Ads-Work-176/t/advertising
[3] Herbert E Krugman – WARC https://www.warc.com/fulltext/JAR/Authors/krugman_he.htm
[4] Consumer Behavior and Advertising Involvement: Selected Works of Herbert E. Krugman (Marketing and Consumer Psychology Series) by Edward P. Krugman | WHSmith https://www.whsmith.co.uk/products/consumer-behavior-and-advertising-involvement-selected-works-of-herbert-e-krugman-marketing-and-cons/edward-p-krugman/hardback/9780805857887.html
[5] Re-Defining Mobile Advertising Frequency http://digitalmarketingmagazine.co.uk/digital-marketing-advertising/re-defining-mobile-advertising-frequency/1205
[6] [PDF] Why Three Exposures May Be Enough https://amsr.contentdm.oclc.org/digital/api/collection/PapersOffprnt/id/9049/download
[7] The ‘Rule of 3’ in digital signage content https://www.digitalsignagetoday.com/blogs/the-rule-of-3-in-digital-signage-content/
[8] Is it such a thing as too much advertising? (Part 1) https://www.linkedin.com/pulse/thing-too-much-advertising-part-1-corneliu-vilsan
[9] Effective Frequency ANA Naples 1979 https://www.scribd.com/document/414380935/Effective-Frequency-ANA-Naples-1979
[10] 4 https://amsr.contentdm.oclc.org/digital/api/collection/PapersOffprnt/id/14358/download
[11] Stop Guessing: The Proven Frequency That Makes Ads Work https://www.gowithbigtime.com/blog/C/2025/09/24/Stop-Guessing-The-Proven-Frequency-That-Makes-Ads-Work-176
[12] A https://amsr.contentdm.oclc.org/digital/api/collection/PapersOffprnt/id/14348/download
[13] Study: Ad overload could pose steeper risk to brands than … https://www.marketingdive.com/news/study-ad-overload-could-pose-steeper-risk-to-brands-than-messages-near-ina/596789/
[14] Ad Overload Could Pose Steeper Risk To Brands– Study https://brandcom.ng/2021/03/23/ad-overload-could-pose-steeper-risk-to-brands-study/
[15] Excessive Ads Negatively Impact Consumers’ View of a Brand More … https://agilitypr.news/Excessive-Ads-Negatively-Impact-Consumer-16717
[16] Ad Fatigue: Data Reports 2026 – WifiTalents https://wifitalents.com/ad-fatigue-statistics/
[17] [PDF] Ad Fatigue: An Investigation into the Cognitive, Emotional and … – ijrpr https://ijrpr.com/uploads/V6ISSUE1/IJRPR38146.pdf
[18] Ad fatigue worsens as 93% of consumers avoid advertising: Study https://communicateonline.me/news/24081/
[19] A new ‘wearout’ standard for a new era of advertising https://www.warc.com/newsandopinion/news/a-new-wearout-standard-for-a-new-era-of-advertising/en-gb/41810
[20] Is Ad Wear-Out Really A Myth? – Creative Salon https://creative.salon/articles/features/qotw-marketing-budgets
[21] Study finds ad effectiveness does not ‘wear-out’ over time https://www.marketingweek.com/study-ad-effectiveness-does-not-decline/
[22] Do Ads Wear Out? – System1 Group https://system1group.com/blog/do-ads-wear-out
[23] Older ads ‘as effective’ as newer ones, says System1 | News https://www.research-live.com/article/news/older-ads-as-effective-as-newer-ones-says-system1/id/5105682
[24] Ad wearout wearout: How time can reverse the negative effect … https://people.duke.edu/~jch8/bio/Papers/Kronrod%20Huber%20ad%20repetition%20IJRM.pdf
[25] How to Reverse the Negative Impact of High Frequency Ads https://todayindigital.com/adfatigue/
[26] Sustainability Starts with Your Ads | System1 Group https://system1group.com/blog/sustainability-starts-with-your-ads-the-case-for-wear-in-not-wear-out
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