By: Dr. James McFarland, Behavioral Scientist
Quick, think of a number between 1 and 10. Got it? Good. Now, if I told you that the number you just picked was lucky, would that change how you feel about your next purchase? According to a growing body of research in consumer psychology, the answer is a resounding yes, and it has nothing to do with four-leaf clovers.
With St. Patrick’s Day upon us, marketers across every industry are dusting off the shamrocks, rolling out the green color palettes, and deploying luck-themed promotions by the truckload. And they should. Americans spent a record breaking $7.2 billion on St. Patrick’s Day celebrations in 2024, a 4.3% increase from the previous year, with an average of $44 per person, and a similar amount in 2025. But here’s the twist that most brands miss: it’s not the theme of luck that matters most to your bottom line; it’s what the feeling of luck does to the brain. And what it does is fascinating.
When Consumers Feel Lucky, They Want Something New
A 2025 study published in PLOS ONE by Zhao and Li set out to answer a deceptively simple question: when people feel lucky, does it change what they choose to buy? Through a series of three carefully designed experiments, the researchers found something that should make every marketer sit up and pay attention. When consumers were primed to feel lucky, through cues as subtle as seeing a price tag ending in a culturally “lucky” number, they became significantly more likely to engage in what psychologists call variety-seeking behavior. In other words, feeling lucky made people want to try something new, different, and unfamiliar rather than sticking with their tried-and-true favorites.
Why? The researchers traced the mechanism to something called novelty-seeking motivation. Luck doesn’t just make us feel good; it makes us feel powerful. According to what psychologists refer to as the “psychological power theory of luck,” perceiving oneself as lucky functions like a kind of psychological superpower. It inflates our sense of personal control, boosts our confidence in uncertain situations, and, critically for marketers, makes us far more willing to take risks. When people feel lucky, the unfamiliar stops being scary and starts being exciting.
There’s an important nuance here, though. The study also found that this effect was strongest among consumers with a high need for cognitive closure, that is, people who typically prefer certainty, structure, and quick, definitive answers. These are the consumers who normally stick with what they know. But when primed with luck, even these cautious buyers opened up to unfamiliar options. For consumers who already had a low need for cognitive closure (the natural adventurers among us), the luck prime didn’t change much because they were already inclined to explore. The takeaway? Luck doesn’t just preach to the choir; it converts the skeptics.
Brands That Are Doing It Right (and the Psychology behind the Strategy)
Let’s look at some brands that, whether they know it or not, are leveraging the psychology of luck beautifully this St. Patrick’s Day season.
McDonald’s and the 50th Anniversary of the Shamrock Shake. Every year, the return of the Shamrock Shake is a masterclass in scarcity and seasonal anticipation. But in 2025, McDonald’s went further by resurrecting Uncle O’Grimacey, a character not seen since the 1970s, tying nostalgic warmth to the feeling of holiday luck. Through the lens of the luck research, this is brilliant: the limited-time nature of the product creates uncertainty (“Will I get one before they’re gone?”), and the festive lucky theming primes consumers to explore the rest of the menu. Remember, lucky consumers are variety-seekers.
Guinness and the “POV” Campaign. Guinness partnered with POV, a disposable camera app, to invite consumers to photograph their St. Patrick’s Day gatherings for an official user-generated content campaign. This taps directly into the ritualistic element of luck perception. Research by Wang and Yin shows that physical, participatory actions in uncertain contexts boost feelings of luck. By giving consumers a ritual, “take a photo of your gathering with Guinness,” the brand creates a behavioral loop that enhances both the emotional experience and the brand association.
What This Means for Your Brand
So how do you translate the psychology of luck into a real marketing strategy? Here are some principles grounded in the research:
1. Prime the Feeling, Not Just the Theme. Slapping a shamrock on your homepage is table stakes. What actually moves the needle is creating a felt sense of luck. Use language, visuals, and interactions that make the consumer feel personally fortunate. Flash sales framed as “Lucky You” promotions, surprise discounts at checkout, or random reward emails all activate the psychological machinery that drives variety-seeking and risk tolerance.
3. Add a Ritual or Interaction. Don’t just tell consumers they’re lucky, let them do something. Spin a wheel. Scratch a virtual card. Shake their phone. Open a mystery box. Research on luck rituals shows that physical or interactive engagement under conditions of uncertainty amplifies the feeling of luck far more than passive messaging.
4. Target the Creatures of Habit. The Zhao and Li study’s most actionable finding may be that luck priming has the greatest impact on consumers who typically avoid variety. Your loyal, repeat buyers, the ones who always order the same thing, are the ones most likely to be nudged toward something new by a luck-themed experience. Consider segmenting your audience and deploying luck-based campaigns specifically to your most habitual customers.
The Bottom Line
St. Patrick’s Day gives brands a once-a-year opportunity to tap into one of the most potent and underutilized forces in consumer psychology: the perception of luck. But as the research makes clear, luck isn’t just a holiday gimmick; it’s a real psychological state that alters how consumers evaluate risk, pursue novelty, and make purchasing decisions. The brands that treat luck as mere decoration will see modest seasonal bumps. The brands that understand the science behind it will see something much more valuable: consumers who are willing, even eager, to try something new.
And in a marketplace where breaking through habitual purchasing patterns is one of the hardest challenges a marketer faces, that’s not luck. That’s strategy.
