Picture two shoppers checking out at a clothing store. One is handed a $20 gift card as a routine thank-you. The other spins a promotional wheel and lands on the same $20 gift card, plucked from a range of possible prizes worth $10 to $30. Objectively, both people walk away with identical prizes. But do they feel the same way about what they got?
A new set of experiments published in the Journal of Consumer Research suggests they do not. According to the study, people consistently prefer goods that emerged from an uncertain promotion over the same goods that were guaranteed from the start, even after the uncertainty has been resolved and the outcome is known. The authors call this pattern the “uncertainty spillover effect.”
A question that lingers after the wheel stops spinning
Retailers have been leaning on uncertainty for a while now. JCPenney has offered mystery coupons at checkout. Priceline sells “pricebreaker” hotel deals where travelers don’t know which property they’ve booked until later. Robinhood hands new users a free stock of unknown value. Prior research has mostly looked at what happens before the uncertainty is resolved: whether people enjoy the anticipation, whether they’ll pay for a mystery prize, whether risky promotions drive purchases.
Beidi Hu of the University of Chicago Booth School of Business, along with Siyuan Yin of Stony Brook University and Alice Moon of Georgetown University, wanted to know what happens after the mystery is solved. Once a customer knows their hotel, their discount, or their gift card value, does the earlier uncertainty still shape how they feel about it? Common intuition says no: a $25 gift card is a $25 gift card. The researchers argue otherwise.
The mechanism: comparing to what could have been worse
The authors’ explanation involves a concept from psychology called counterfactual thinking, meaning the mental “what if” comparisons people make between what actually happened and what could have happened. Positive outcomes tend to trigger “downward” counterfactuals, where people compare their result to worse possible alternatives. Winning a bronze medal, for example, often feels better than winning silver because bronze medalists compare themselves to fourth place, while silver medalists compare themselves to gold.
Hu and her colleagues propose that uncertain promotions naturally prompt these downward comparisons. When your $20 gift card came from a wheel that could have landed on $10, the worse outcome feels vivid and easy to imagine. That “narrowly avoided” alternative makes your actual prize seem more attractive. When the $20 gift card was simply handed to you, there’s no worse alternative floating in your mind.
Seven experiments and 12,000 participants
The team ran seven preregistered experiments involving a combined 12,128 people. The first study used a realistic hotel booking scenario adapted from Priceline. Participants either saw a hotel offered at a discount as part of a three-hotel mystery deal, or the same hotel offered at the same discounted price with no mystery involved. About 89% of participants in the mystery version chose to book, compared to 76% in the straightforward version.
The second study attached real money to the decision. Participants were told that ten of them would have their choices actually enacted. Some received a $25 Amazon gift card outright; others “won” the same $25 card from a lottery with prizes ranging from $15 to $35. They then chose between keeping the card and taking a 50-50 gamble between $10 and $40. Those whose card came from the lottery were more likely to keep it (61% versus 55%).
The third study tested the counterfactual explanation directly. After making their choice, participants rated how much they had thought about worse alternatives while deciding. Those in the “previously uncertain” condition reported significantly more downward counterfactual thinking, and this difference statistically accounted for their stronger preference for the original prize. The same participants did not report thinking more about better alternatives, nor did they report feeling more surprised, which the researchers use to argue against alternative explanations.
Testing the boundaries
If the effect really runs through downward comparisons, then situations that eliminate those comparisons should eliminate the effect. The next three studies probed this logic.
Study 4 made a downward counterfactual salient for the always-certain condition, telling participants that the previous customer received a smaller $10 gift card. When this comparison was highlighted, the gap between the uncertain and certain conditions disappeared: both groups preferred their $20 card at similar rates. Adding a losing counterfactual to the certain condition seemed to close the gap.
Study 5 gave some participants the worst possible outcome of an uncertain lottery, a $20 gift card from a lottery ranging up to $60. When people received the bottom of the range, they no longer preferred the previously uncertain card over an always-certain one. In fact, roughly one in five kept it in either condition. Without any worse alternative to point to, the spillover effect vanished.
Study 6 flipped the situation into the loss domain. Participants faced cards worth negative amounts of money, meaning they would lose $50 either way. Here the pattern reversed. Only 25% of participants kept a previously uncertain loss, compared to 32% who kept an always-certain loss. The researchers interpret this as consistent with their framework: losses trigger upward counterfactuals (thoughts about how it could have been better), and imagining “I could have only lost $20 instead of $50” makes the actual loss feel worse.
The spillover reaches other purchases
The final study looked at whether the effect extends beyond the original prize itself. Participants imagined signing up for a free trial of a $25-per-month coffee subscription, which came with a complimentary sample. Some received their Italian coffee sample as a random draw from five possible options; others were simply given the same Italian sample. Participants then decided whether to keep or cancel the paid subscription.
Those whose sample came from a mystery draw were more likely to keep the subscription (45% versus 39%). The authors interpret this as evidence that positive feelings about the prize can carry over to related products from the same company.
What this means for shoppers and sellers
For marketers, the authors suggest that layering uncertainty into promotions may increase how much customers value what they eventually receive, and may even boost interest in follow-up purchases. They also flag a warning: the reversal in the loss domain implies that mystery pricing tied to potential losses, such as surge pricing or hidden fees, could push customers away rather than toward a brand.
For consumers, the findings offer a small nudge toward self-awareness. The satisfaction you feel about a coupon, a prize, or a hotel deal may be shaped less by the thing itself and more by the alternatives your mind conjures up. The researchers found the effect held in various settings, but it depended on outcomes being comparable on a clear scale (dollar values, quality ratings) rather than differing by taste. When people are choosing between mystery flavors or store brands with no obvious “better” or “worse,” the spillover weakened.
The authors are careful to note what their evidence does not support. Their measurements found no signs that surprise or heightened emotion accounted for the pattern, and psychological ownership doesn’t fit the reversals they observed with losses and worst-case outcomes. They present downward counterfactual comparison as the most consistent explanation for the results they gathered, while acknowledging that surprise and counterfactual thinking are intertwined enough that real-world settings likely involve both.
