Behavioral economics & viral marketing case studies
Life Event Effect 
Details
Life Event Effect means that people are more likely to switch habits and brands when they have undergone a life event. Changes like moving, having a child, starting a new job, or a breakup make old habits break.
Think of someone who just moved to a new city. They suddenly choose new brands, new routines, and new services , not because the products changed, but because their life context did.
In marketing this bias explains why timing matters so much. Brands that show up during life changes get a rare chance to form new habits.
Life Event Effect 
Guide
Life Event Effect 
Research
About 34% of US soldiers used heroin while fighting in Vietnam, and around 20% showed signs of addiction. After a major life change (coming back home) this behavior dropped fast.
In the first year after returning to the US, only about 1% became addicted again, even though 10% tried the drug again after returning.
This shows that when life context changes, behavior can change suddenly, even without treatment.
During research, researchers ran a survey among 2,370 people. They asked two things:
Overall, 21% of people who had a recent life event had switched brands, vs 8% of regular consumers (≈2.6X higher). And in 3 categories, life-event consumers were more than 3X more likely to have switched brands.
People whose age ends in “9” (eg, 29, 39, 49) are more likely to question the meaningfulness of their lives than people at other ages.
In their study, researchers examined the ages of first-time marathon runners and found that 9-enders were overrepresented by ~48% among participants aged 25-64.
Nine-enders were also more represented on an extramarital affairs site (men with ages ending in 9 were ~18% overrepresented).
This explains the whole idea of a midlife crisis.
Life Event Effect 
Examples
1. Starting new job - LinkedIn Premium, Notion, Slack
A new job resets tools, routines, and identity. LinkedIn usage spikes when people start searching for a new job. LinkedIn Premium converts best when users change job titles. Notion and Slack get adopted because teams rebuild workflows from zero.
When people move, they switch internet, furniture, and home services. Comcast and AT&T aggressively target people right after an address change. IKEA wins because moving breaks old habits, and people are open to new brands.
Underdog Effect Details
Underdog Effect means we root for people or brands that seem disadvantaged but still fight hard. It’s about telling a story of a small start, low budget, a big competitor to fight, and steady effort against tough odds. Effort against the odds makes us feel emotionally connected.
Think of a tiny startup showing how they build everything with almost no money while going up against a huge company. Their honesty and effort make you want them to win.
In marketing this bias shapes storytelling, brand positioning, and challenger messaging. When customers see a brand as the scrappy fighter, they support it more actively.
Underdog Effect Guide
Underdog Effect Research
The researchers found that the Underdog Effect makes people more likely to buy, choose, and stay loyal to a brand.
This effect is even stronger for people who see themselves as underdogs, especially when they are buying something for themselves, not for others. It also works better in countries where underdog stories are an important part of the culture.
Underdog Effect Examples
1. Apple's "1984" commercial
In its early days, Apple positioned itself as the underdog against the giant IBM. Their now iconic "1984" commercial, showed a dystopian future dominated by "Big Brother" (IBM), with Apple as the rebellious force breaking the mold. This ad solidified Apple's reputation as the innovative and rebellious alternative to the status quo.
Avis, the car rental company, was always in the shadow of Hertz, who was an industry #1. Avis used this situation to their advantage with their "We Try Harder" campaign. Because they were #2 in the market, they had to put in extra effort to please their customers. This campaign was immensely successful and helped Avis increase its market share.
When a newly-created Instagram account of an egg announced that it wanted to beat Kylie Jenner in terms of the most-liked photo, people responded. A simple egg photo collected over 52M likes within days.
Features to Benefits Details
Features to Benefits means people care less about what a product has and more about what it does for them. A feature is technical, a benefit is how that feature improves someone’s life.
Think of a blender advertised as having “1200 watts.” Most people don’t know what that means. But say “blends smoothies in 10 seconds,” and suddenly it clicks.
In marketing this shift shapes product pages, ads, emails, and demos. Explaining benefits helps people imagine the outcome, not the mechanics, which makes decisions much easier.
Features to Benefits Guide
Features to Benefits Research
Old launcher
D - Free town
EA ran a controlled A/B experiment inside The Sims 3 game launcher to understand whether feature-oriented messaging or benefit-oriented messaging would drive more players to register their game.
The control (old launcher) was the standard launcher screen that showed many competing messages, generic registration benefits, and unclear reasons to sign up. Registrations from this control were low.
EA then tested 6 new variants, each representing a different style of messaging:
Every tested variant outperformed the old launcher, with lifts of +43% or more.
But the biggest finding was the gap between features and benefits:
All feature-style variants (A1, A2, B) performed worse than any specific-benefit variant.
Features to Benefits Examples
1. Apple
Feature: 5GB of storage.
Benefit: 1,000 songs in your pocket.
Apple didn’t sell storage. They sold a lifestyle upgrade in one sentence.
Feature: Organized channels, file sharing, app integrations.
Benefits: Slack users experience 48,6% fewer emails since they started using the platform.
Slack sells relief from overwhelm, not software tools.
Bandwagon Effect Details
Bandwagon Effect means we’re more likely to choose something when we see many others choosing it. Popularity acts like proof.
Think of hearing that everyone is watching a new show. Even if you weren’t interested before, you feel a pull to check it out, partly to fit in, partly to not feel left out.
In marketing this bias powers social proof, bestseller tags, reviews, waitlists, and visible community numbers. When people see a crowd, they assume the choice is safe and worth joining.
Bandwagon Effect Guide
Bandwagon EffectResearch
The study examined the bandwagon effect in luxury buying. It focused on how much people want a luxury product when they believe popular or high-status people already use it.
The researcher ran 3 experiments with 60 teenagers, 76 female students, and 73 male students/graduates.
When people saw a message saying “popular people use this product,” several things changed:
The study clearly showed that the bandwagon effect works: when a product is linked to an admired group, people want it more, pay more, and choose options that signal status.
Cialdini’s famous hotel-towel study showed that people follow the bandwagon effect.
Guests saw 3 messages:
Message #2 increased towel reuse by 26%, and the message #3 increased it by 33%, making it the most effective. The study proved that people follow what others do, especially when the group feels close or similar to them.
Bandwagon Effect Examples
1. Clubhouse
When Clubhouse launched, people rushed in not because they needed audio chats, but because thousands of others were already inside. The invite-only system made it feel like a growing party you didn’t want to miss. The Bandwagon Effect created explosive growth to 10M weekly users before the hype faded.
Game of Thrones became a cultural event partly because huge numbers of people were already talking about it - memes, spoilers, theories, and reactions filled the internet every week. Even people who normally don’t watch fantasy felt pressure to join in, just to understand conversations at work or avoid feeling left out. The Bandwagon Effect turned the show from a niche book adaptation into one of the biggest global TV phenomena, reaching over 19M viewers for the finale.
TBH grew insanely fast because its viral loop was engineered to spread inside one school at a time, not across a whole city or country. When the app launched in a new school, hundreds of students got the same notifications, polls, and compliments at once, creating the feeling that “everyone here is using it.”
This hyper-local explosion triggered a powerful Bandwagon Effect. Once a few classmates joined, the whole school rushed in, because no one wanted to be the only person not included.
TBH hit millions of downloads in weeks, not because the app was global, but because each school became its own viral ecosystem driven by social pressure and FOMO.
Nostalgia Effect Details
Nostalgia Effect means we respond more strongly to things that remind us of the past. Memories, old styles, and familiar moments create warm feelings that lift our judgment.
Think of hearing a song from your childhood and instantly feeling more positive, even if your day was stressful. The memory colors the moment.
In marketing this bias shapes retro packaging, old-school branding, classic sounds, and “remember when” campaigns. Nostalgia makes products feel safer, warmer, and more meaningful.
Basically, the past makes the present feel better.
Nostalgia Effect Guide
Nostalgia Effect Research
This research ran 6 experiments. In every experiment, nostalgia made people value money less or want money less.
Key findings:
Nostalgia increases social connectedness (people feel closer to others). When this social need is filled, people feel safer and less focused on self-protection or financial security. Because of that, money becomes less important, so they are more willing to spend or give.
When nostalgia is activated (ads, memories, old products, retro style), people spend more easily because they feel emotionally full and less attached to their money.
Nostalgia Effect Examples
1. Pokémon GO
Pokémon GO exploded in 2016 because it brought back childhood memories of collecting creatures. Millions of adults who hadn’t played games in years returned because the app made them feel like kids again. Nostalgia powered record downloads, global crowds, and $500M revenue in the first 60 days.
Stranger Things became a global hit because it recreated the exact look and feel of 1980s movies: neon colors, synth music, walkie-talkies, arcade games, and Spielberg-style adventure.
Adults who grew up in the 80s and 90s felt a strong emotional pull. The show reminded them of childhood summers, old friendships, and classic films. This nostalgia made people binge the series, share it like crazy, and turned a mid-budget show into one of Netflix’s biggest cultural phenomena.
Humor Effect Details
Humor Effect means we remember things better when they make us laugh. A joke, a funny twist, or a light tone sticks in the mind far longer than something serious and flat.
Stories & humor are the ultimate shortcuts to deeper connections and earning trust of your customers. Humor bypasses skepticism.
Think of seeing a billboard with a clever joke. Even if you glance at it for a second, the line stays with you, while dozens of normal ads disappear instantly.
In marketing this bias shapes brand voices, ads, emails, and social posts. Humor boosts attention, recall, and shareability because it gives the brain a little reward for paying attention.
Humor Effect Guide
Humor Effect Research
This meta-research from 1992 reviews dozens of studies on how humor works in advertising.
Humor grabs attention very well but does not always convince people. About 24% of TV ads used humor, and 94% of advertisers said humor is an effective way to get attention, while 55% of research directors said humor works better than non-humor ads for attention.
Humor consistently lifts attention, but its effect on understanding the message is mixed, with:
Humor also does not guarantee stronger persuasion, although one analysis from 1982 found that 31% of humorous ads performed above average in persuasion tests.
The strongest finding in the entire review comes from the role of liking. A large 1991 study with almost 15,000 interviews showed that liking a commercial predicted which ad would win in sales 87% of the time, and a simple like-or-not-like measure predicted success 93% of the time.
People who liked a commercial a lot were also twice as likely to be persuaded. Humor supports this effect because when people felt an ad was funny or clever, it predicted success 53% of the time, while calling an ad boring predicted failure 73% of the time.
Overall, humor is great for getting attention and increasing liking, and since liking is one of the strongest predictors of sales, humor can indirectly make ads more effective, especially when the humor is connected to the product and used for simple, low-involvement decisions.
Humor Effect Examples
Their first ad used deadpan humor, swearing, and absurd scenes to explain a boring product: razor subscriptions. The humor made the message unforgettable, “Our blades are f***ing great.”.
Result: over 12k orders in 48 hours and a company later sold for $1B.
After the 2008 shoe-throwing incident became global meme material, Alex Tew created a funny browser game called Sock and Awe in just 3 hours.
The humor made it instantly shareable. By day 3, it had been played 1.4M times, and by day 6, the site reached 9M visitors.
The game was sold within days, and the team later used the traffic to collect 120k emails, helping them launch their next project (PopJam).
Old Spice used surreal, rapid-fire humor that completely broke deodorant-ad conventions. The absurd style made the brand memorable to both men and women, turning a dying product line into a cultural hit. Sales jumped 125% year-over-year after the campaign.
Framing Effect Details
Framing Effect means the way information is presented changes how we feel about it, even when the facts stay the same. The frame shapes the reaction.
Think of hearing that a product is 90% effective versus hearing it has a 10% failure rate. Same numbers, but one feels safe while the other feels risky. The wording sets the mood.
In marketing, highlighting gains feels motivating, highlighting losses feels urgent, and shifting perspective can make the same offer look far more attractive.
Framing Effect Guide
Framing Effect Research
People were told a disease would kill 600 people. They had to choose between two programs.
The options were identical, only the wording changed.
1. Gain frame (positive)
Results:
2. Loss Frame (negative)
Results:
Same math. Different frame. Completely different behavior.
Framing Effect Examples
1. BetterHelp
Betterhelp therapy reframes therapy as normal self-care. The homepage frames depression as something normal. This reduces stigma and makes the purchase feel proactive, not reactive.
Liquid Death framed water as rebellious “Murder Your Thirst” beverage. They took a boring product (water) and reframed it as a punk, metal, anti-plastic energy-drink vibe.
Scarcity Details
Scarcity means we value things more when they feel limited. When supply drops, desire rises, even if nothing else changes.
Think of seeing only a few items left on a shelf. Suddenly the product feels more important, even if you didn’t want it a minute ago. The fear of losing it boosts the urge to act.
In marketing scarcity turns hesitation into action. Limited spots, low stock, and short windows make people move faster because waiting feels risky.
Scarcity Guide
ScarcityResearch
A large meta-analysis of 131 studies and 416 effects found that not all scarcity works the same.
A group of 200 female students rated how attractive cookies were when there were many of them (abundant), when there were few (scarce), and when the amount changed. When cookies became scarce, the students were told it happened either because many people wanted them or because of an accident.
As a result, the cookies were rated more desirable when they were scarce than when they were abundant.
They were also rated more valuable when they changed from abundant to scarce compared to being scarce the whole time.
Scarcity caused by high demand got the highest ratings, while “accidental scarcity” scored lower. And cookies that stayed abundant the whole time were rated higher than cookies that started scarce and later became abundant.
Scarcity Examples
When Snap released Spectacles, you could only buy them from special vending machines called Snapbots. They appeared in random places without warning, so it felt like a surprise game of first come, first served.
This unpredictable availability created strong FOM and as a result, Spectacles became a cult gadget.
MSCHF releases strange products in small, surprise drops. You never know when the next drop comes, and they never restock, so people rush to buy. This makes every product feel rare, special, and worth grabbing fast.
TBH launched only in a few high schools and only in one state at the start, nobody else could download it. This created massive FOMO in nearby schools. Because of that (and many other brilliant aspects), the app was downloaded 5M times within 2 months.
Curiosity Gap Details
Curiosity Gap means we feel a strong pull to fill in missing information. When we see a hint without the full answer, our brain wants to close the gap.
Think of reading a headline that teases a surprising fact but doesn’t give the full story. You click because the missing piece bothers you just enough to take action.
In marketing this gap drives engagement. Teasers, questions, partial reveals, and open loops make people lean in because they want to know what comes next.
Curiosity Gap Guide
Curiosity Gap Research
In a study from 2007, people chose between a sure thing (cash) and a mystery prize. When the researchers gave them just a little information about the mystery box (not the whole truth), curiosity shot up. People became more than twice as likely to choose the unknown prize instead of the cash. That small tease created a curiosity gap, and the urge to learn the missing info pushed them to take the risk.
A large analysis of 8,977 headline A/B tests found that headlines with an optimal “curiosity gap” achieved the highest CTR.
Upworthy’s data showed that only ~9% of very vague headlines gained clicks by adding info, whereas over 50% of overly detailed headlines actually saw ~5–10% fewer clicks.
This supports Loewenstein’s information-gap theory: headlines that leave readers guessing (not too little, not too much) can boost engagement.
Research on email marketing showed that using curiosity gap can lift open rates. In one study, 33% of recipients opened an email solely due to a compelling, curiosity-inducing subject line. Adding personalization further amplified this effect - personalized, curiosity-gap subject lines saw open rates climb by ~35%.
Curiosity Gap Examples
Ogilvy put a cheap eye-patch on a perfectly normal model wearing Hathaway shirts. This made people instantly curious about the model.
The first ad ran in The New Yorker in 1951. Within a week, every Hathaway shirt in New York was sold out.
In 2004, Heyah flooded cities with a strange red hand logo and a website called “nadchodzi.pl” (“it’s coming”) - but didn’t reveal the brand.
People kept asking “What is this? Who is behind it?” The curiosity gap exploded, driving 1.2M unique visitors before launch.
When the reveal finally came, Heyah got over 300k users within the first month.
Affect Heuristic Details
Affect Heuristic means we make decisions based on our immediate feelings instead of careful thinking.
How we feel shapes how we see risk and reward. When people feel good they are more likely to take risks and focus on potential great rewards. But when their mood turns dark they may become more risk-averse and focus on potential losses. This swing of emotions can tip the scales in how choices are made.
Think of choosing a product simply because it gives you a good vibe, even if you didn’t compare features or prices. The feeling made the choice for you.
In marketing this heuristic shows why mood, colors, music, faces, and tone matter. Positive feelings make risks seem smaller and benefits seem bigger.
Affect Heuristic Guide
Affect HeuristicResearch
95% of our purchasing decisions are emotional. Most of our buying decisions come from the subconscious. We think we’re comparing features and prices, but in reality we react to emotions, associations and mental shortcuts we don’t notice.
After looking at 1,400 ad campaigns from the last 30 years, the study showed that ads focused just on emotions almost doubled the success rate (31% profit boost) compared to those that stuck to facts and logic (16% boost).
One field study showed that hungry shoppers spent 64% more money and grabbed more items even non-food ones.
In a lab test, hungry students took 50% more binder clips than students who had eaten. They didn’t suddenly “love” binder clips. Hunger just created a general urge to grab more stuff. Hunger boosts the desire to consume anything, not just food.
Retailers like Trader Joe’s or Home Depot offer free coffee to their customers. And if you drink coffee before you shop, you’re likely to buy 30% more items and spend roughly 50% more money.
Works for the feel-good products - scented candles, fragrances, home decor. Not so much for practical things like notebooks or kitchen utensils.
Affect Heuristic Examples
1. Starbucks
Starbucks doesn’t just sell coffee. It sells warm lighting, cozy music, and the smell of fresh beans. This positive emotional atmosphere creates a comfort halo. Because customers feel good in the space, they perceive the coffee as higher quality and the price as more reasonable, even though logically it’s much more expensive than competitors. The pleasant vibe lowers the perceived risk of overpaying.
Tesla owners often report extremely positive feelings toward Elon Musk and the brand. That emotional attachment makes many buyers gloss over objective risks like build-quality issues, recalls, or long repair times.
The cool, futuristic, mission-driven vibe creates positive affect, which leads to quick, intuitive decisions like Tesla = innovative = safe/best choice, even when data doesn’t fully support it.