Behavioral economics & viral marketing case studies
Fundamental Attribution Error 
Details
The Fundamental Attribution Error means we explain other people’s behavior by their personality, not their situation. We assume who they are matters more than what’s happening around them.
Think of someone cutting you off in traffic. You instantly label them as rude or careless, without considering they might be late, stressed, or dealing with an emergency.
In marketing this bias shapes how people judge brands, founders, and customer behavior. One mistake gets blamed on character instead of context, which can quickly damage perception.
The Fundamental Attribution Error 
Guide
The Fundamental Attribution Error
Research
The research studied how consumers explain product failures and how those explanations change their reactions to a brand.
Participants were given scenarios where a product did not work as expected. The situations were designed so the failure could be caused either by the company (design, quality, instructions) or by the situation/user.
Then researchers measured emotions, satisfaction, and behavioral intentions.
The results showed a clear Fundamental Attribution Error: people strongly blamed the company, even when the situation was unclear.
When consumers believed the failure was the firm’s fault, they felt more anger, were less satisfied, and were much more likely to complain, ask for refunds, or switch brands.
When the failure was explained as situational, negative reactions were much weaker.
The Fundamental Attribution Error 
Examples
1. Restaurant reviews
A customer waits too long for food and writes a bad review about lazy or rude staff. The real cause could have been understaffing, peak hours, or a simple misunderstanding. Sometimes you just can't do anything about it, even if you try (see the pic above).
Hindsight Bias Details
Hindsight Bias means that after something happens, we convince ourselves we “knew it all along.” The outcome suddenly feels obvious, even if it wasn’t at all before.
Think of hearing that a startup finally blew up. Right away your brain starts saying, “Yeah, of course. The idea was brilliant.” But before success, you probably had no clue it would work. The story gets rewritten to feel predictable.
In marketing this bias shapes how people judge campaigns, trends, or product launches. Wins look inevitable, failures look stupid, and real uncertainty gets erased.
In other words, we rewrite the past to make ourselves feel right.
Hindsight Bias Guide
Hindsight Bias Research
Before President Nixon’s historic 1972 trips to China and the USSR, researchers asked students to predict various outcomes.
Months later, after the events, the students were asked to recall their predictions. A whopping 84% showed hindsight bias - they remembered themselves as having predicted the actual outcomes with higher certainty than they originally had.
In short, once they knew what happened, they overestimated how predictable it was and how accurate their foresight had been.
Sports fans routinely insist they knew their team would win (or lose) after the game is over, even if they were unsure before.
Similarly, investors looking back on a stock market crash often recall having foreseen it, inflating their past confidence.
Studies confirm that once an outcome is known, around 20-30% more people claim they predicted it, and individuals remember giving higher odds for it than they actually did.
Hindsight Bias Examples
1. Netflix
After Netflix became huge, people said it was obvious that streaming would win. But at the time, most analysts doubted the model and Blockbuster laughed at it. Hindsight Bias makes everyone believe the success was predictable… when in reality almost nobody believed in it early on.
Today people say Nokia’s fall was predictable, but at the time, Nokia was the world leader, smartphones were tiny niche toys, and most experts believed Nokia would stay on top. Hindsight Bias makes the crash look obvious now, even though almost nobody predicted it when it actually mattered.
Sunk Cost Effect Details
Sunk Cost Effect means we keep investing time, money, or energy into something just because we’ve already put a lot into it, even when quitting would be smarter. The past effort traps us.
Think of staying in a bad project just because you spent months on it, even though it doesn't earn any money. Or you're stuck in a bad relationship even though you don't love the other person anymore. The time you already invested pulls you in, not the actual value.
In marketing this effect keeps customers subscribed, committed, or loyal to things they’ve already paid for or spent effort on. The more they’ve put in, the harder it feels to walk away.
Sunk Cost Effect Guide
Sunk Cost Effect Research
In a 1985 study by Arkes and Blumer, people got theatre tickets at different prices:
54 people who paid more for a theater season pass ended up going to more shows over 6 months, just to use their pricey ticket. The cheaper the ticket, the less likely people were to use it.
Sunk Cost Effect Examples
1. Starbucks rewards
Starbucks gives you points that expire. When you have something like 70/100, you don’t want that effort to go to waste. So you buy another coffee or two just to “finish the set.” The more points you’ve collected, the stronger the pull.
People spend thousands on the Peloton bike. After that, they feel they must keep the monthly subscription active, or else that big investment feels wasted. The high upfront cost keeps them inside the system much longer.
Cognitive Dissonance Details
Cognitive Dissonance means we feel uncomfortable when we hold two conflicting beliefs or our actions and beliefs don’t match. The mind hates this tension and tries to reduce it fast.
Think of someone who buys an expensive product they don’t really need. To ease the discomfort, they start convincing themselves it was a smart decision, even if it wasn’t. The story changes to fit the action.
In marketing this effect shows why people justify purchases, ignore flaws, or defend brands they’ve already chosen. Once they commit, they shape their beliefs to feel consistent.
Cognitive Dissonance Guide
Cognitive Dissonance Research
Classic studies showed that after making a choice, people often increase their positive feelings for the chosen option and diminish their liking for the option they rejected.
In one study, shoppers were asked to rank household items and then choose one to keep. Later, they ranked the items again - and lo and behold, the item they chose climbed higher in attractiveness while the one they passed up fell in their ratings.
Lipponen looked at many older studies to see what people do when they feel unsure after buying something. The research he reviewed showed the same pattern: after a purchase, people try to remove the uncomfortable feeling by:
The final result is that customers use predictable, repeated behaviours to calm down their “did I choose right?” feeling.
Cognitive Dissonance Examples
1. Amazon reviews
After buying something online, people often feel a small worry that they may have picked the wrong product. Amazon reduces this discomfort by showing tons of reviews, star ratings, customer photos, Q&A sections, and the Amazon’s Choice badge.
Seeing that many other people bought and liked the item calms the brain and removes that uneasy feeling after purchasing.
Endowment Effect Details
Endowment Effect means we value things more simply because we own them. Once something feels like ours, its worth rises in our mind.
Think of trying to sell an old item you barely use and being shocked that others won’t pay the price you think it deserves. You see more value in it because it’s yours.
In marketing this effect makes trials, personalization, and early ownership work.
Endowment Effect Guide
Endowment Effect Research
Researchers gave one group of people a coffee mug and asked how much they’d sell it for, and asked another group how much they’d pay for the same mug.
Sellers asked for $7.12, while buyers were only willing to pay $2.87. Sellers were willing to pay almost 2.5X more for the mug! Same mug, same quality, but owning it made people value it more.
Endowment Effect Examples
1. Amazon Prime
That's how Amazon’s 30-day free Prime trial works. Once you’ve experienced free shipping on every order and started relying on it, you feel like Prime membership is something you have, and letting it lapse feels like losing a benefit you own
IQOS used the endowment effect with free 30-day trials.
You don’t just hear about the product – you own it for a month. You get used to less smell, the “healthier” feeling, the new routine. After 30 days, giving it back feels like a loss, so you’re more likely to keep (and buy) it.
They even swapped tests for your pack of cigarettes or lighter, nudging you to “trade in” the old habit for the new one.
Peak-End Rule Details
Peak-End Rule means we judge an experience mostly by its best or worst moment and how it ended, not by the whole thing. The highlights shape the memory.
Think of a long trip with some boring parts, but one amazing moment and a smooth trip home. You remember it as great because the peak and the ending were strong.
In marketing this rule shapes how people recall brands. A single standout moment and a clean, positive finish can outweigh a dozen average interactions.
Peak-End Rule Guide
Peak-End Rule Research
In this study, participants did two uncomfortable tasks.
Objectively, Trial B was longer and caused more total pain.
But after doing both, participants were asked which trial they would choose to repeat.
65% chose the longer and objectively worse trial B.
Since Trial B ended with slightly less pain, the whole experience felt better in memory.
Peak-End Rule Examples
1. Eleven Madison Park
Eleven Madison Park is the restaurant behind Unreasonable Hospitality book, and often called the best in the world. A lot of scenes you see in The Bear series are also inspired by this place.
They always create at least one big “wow moment” for each guest, usually a small surprise or a personal touch. They focus on ending strong too, like giving a final glass of wine or whisky and saying a warm goodbye.
The Magic Castle is the second-best hotel in Los Angeles by TripAdvisor. It focuses on one or two outstanding moments - the popsicle helpline.
Any time, day or night, you can pick up the old-fashioned red phone by the pool and dial the helpline. A man, complete with white gloves, promptly appears bearing a silver platter with a selection of free ice-lollies.
Empathy Gap Details
Empathy Gap means we’re bad at predicting how we’ll feel in a different state of mind. When we’re calm, we can’t imagine being angry or scared. When we’re upset, we can’t remember what calm even feels like.
It’s a blind spot in how our emotions work. The moment we switch states, our brain forgets what the other side felt like. That’s why people make promises they don’t keep or underestimate how strong cravings, fear, or pain can be.
Think of trying to comfort someone heartbroken while you’re happy. It’s hard to really feel their pain. Or planning to eat just one cookie before you’re actually hungry.
In marketing this gap decides how people buy. When someone’s in an emotional state such as hungry, excited, or scared of missing out, logic loses power. The more you understand their current mood, the easier it is to reach them.
Empathy Gap Guide
Empathy GapResearch
Dr. Johannes Hattula’s research found that empathy in marketing can backfire. In 4 experiments on product managers asking them to predict customer preferences in market tests, he and his team discovered that the more empathetic the marketers felt, the worse they performed at predicting customer preferences and motivation.
When marketers tried to “think like consumers,” they actually projected their own tastes more strongly. Instead of reducing bias, empathy made them assume that customers liked what they liked. Even when given real market data, empathetic marketers often ignored it and trusted their own opinions. But when they became aware of this bias, they made more objective decisions.
Effie and Ipsos’ 2025 report “The Intuition Illusion” shows that many marketers trust their gut too much and don’t really understand their audience.
After studying 5,000 US ads, they found that ads combining creativity and empathy are 20% more effective, but only 10% of brands manage to do both.
The report says the main reasons are:
Nearly half of marketers rely mostly on intuition when writing creative briefs, which leads to bias instead of real understanding. True insights, the report explains, go beyond simple observations; they uncover why people act as they do.
Empathy Gap Examples
1. Air Jordans
Nike conducted research to understand what Michael Jordan meant to teens and college students.
The NBA player was more than an athlete. Jordan represented meaning and hope. This hinted he would become an inspiration not just for one particular group of people, but across cultures and generations.
Pepsi ran an ad where Kendall Jenner left a photo shoot to join a protest, clearly inspired by BLM, and handed a police officer a Pepsi that somehow ended the conflict.
Long story short, people hated it. It came off as tone-deaf and fake.
The empathy gap was huge here. Don’t use real social struggles to sell products. If it feels forced or exploitative, the audience will turn on you. Authenticity always wins.
Bud Light sent a custom can to Dylan Mulvaney and featured her in a small promo video.
There was a massive backlash from its core audience - mostly blue-collar male drinkers - who saw it as a political statement.
Bud Light’s backlash cost the brand an estimated $1.4B in lost US revenue and a drop of over 20% in sales shortly after the controversy.
Loss Aversion Details
Loss Aversion means losing something feels much worse than gaining the same thing. Our brains treat losses as threats, so we react stronger to the idea of losing than to the idea of winning.
Think of finding $100 on the street versus losing $100 from your wallet. The pain of the loss hits much harder than the joy of the gain, even though the amount is the same.
People protect what they already have, so messages about losing access, missing benefits, or giving up results work better than promises of new perks.
Loss Aversion Guide
Loss Aversion Research
Researchers tested 4 short messages on a real e-commerce site to see how they change what people do. Each message used a different bias: countdown, social proof, loss aversion, or gain frame. They measured pageviews, time on page, and conversions.
Countdown (“Order in X minutes for fast delivery”)
Bandwagon (“100+ people ordered this”)
Loss Aversion (“This meal is almost gone, don’t miss it”)
Gain Frame (“Order faster, get it faster”)
All messages made people browse more, but only the loss-aversion message increased buying (+23% vs control).
Winning $100 feels good, but losing $100 hurts roughly 2X more, confirmed in many studies.
Loss Aversion Examples
1. Email marketing & cart abandonment
Use subject lines that focus on what people might lose, “don’t lose your 20% off” or “your cart is about to expire.”
Sellers usually push these by highlighting what you could lose. Instead of “get peace of mind with a warranty,” they say “without it, one repair could cost you $2k.” This taps into our fear of losing money or a working product, and it’s often more convincing.
Many programs give you something first and then warn you that you might lose it. A credit card might give you Gold status for 3 months and say “keep spending to keep it”, so you spend more. Hotels give bonus points that expire soon, so you book a stay to not lose them. Starbucks drops bonus stars in your account and says they’ll vanish, which pushes you to visit.