By Dylan Walsh

What good is a mistake?

Not much, says conventional wisdom. Avoid mistakes. And if you make one, at least don’t go around advertising it.

Straightforward logic underpins this assumption, and it’s logic that Taly Reich, associate professor of marketing at Yale SOM, has been questioning since graduate school, when one of her professors lamented in front of class that he hadn’t been more programmatic in his research. Colleagues who had been programmatic, the professor explained, had also been more successful. Here her professor was, publicly admitting where he’d gone wrong and encouraging students to take a different road.

The lesson stuck, but so did something else. “It made me wonder: might people who have a history of making mistakes actually be more persuasive?” says Reich. Did the mention of error subtly imbue her professor’s plea with greater strength? “Can there be an upside to making mistakes?”

A new paper in the Journal of Marketing suggests there can be. With Sam Maglio of the University of Toronto, Reich looked at consumer reviews of different products and found that shoppers were more likely to purchase a product after reading reviews that admitted to making a prior purchase mistake.


Read the study: “Featuring Mistakes: The Persuasive Impact of Purchase Mistakes in Online Reviews”

In one experiment, Reich and Maglio offered study participants a choice between two brands of headphones. The participants read one of two reviews that were identical in their recommendation except that one reviewer admitted to having made a mistake the last time he purchased headphones. This review, it turns out, proved more effective: 93% of participants opted to buy the headphones that this reviewer recommended, while 79% of participants followed the advice of the reviewer who had not made a prior mistake.

Reich and Maglio also confirmed these results under more realistic conditions. In one case, two groups of participants read 10 real Amazon reviews of Altoid mints; one group saw a review that mentioned having made a previous mistake, while the other group did not. At the end of the study, participants were told they could choose either an additional dollar of compensation or a pack of Altoids. In the condition where one of the reviews mentioned a mistake, 35% of participants opted for the mints. In the “no-mistake” condition, only 22% did. In another real-life case study, Sephora customers considering hair care products thought reviews were more helpful when they described a prior purchase mistake.

Driving these results, says Reich, is “perceived knowledge, perceived expertise.” Admitting to having made a mistake inherently conveys that the mistaken reviewer has gained new expertise as a result of the mistake; these reviewers are considered more expert than their peers who never made a mistake. 

Importantly, this result holds only when the product under review and the product that proved a mistaken purchase are of a similar type: if somebody in their review of speakers describes how they previously bought the wrong printer—a case that Reich and Maglio tested—this admission holds no persuasive power. The product domains are too far apart. Also, if a reviewer describes making an egregious or very basic mistake, this may signal incompetence rather than expertise.

The results of this study fit neatly into a broader stream of Reich’s work that examines “when we value unintentional action,” as she puts it. While this study demonstrates how consumers interpret mistakes by their peers, another article demonstrates the way they view mistakes by companies: copping to a mistake can make companies appear more likely to achieve their goals. A third article in the triad looks at mistakes through the lens of products. Reich finds that consumers often prefer products made by mistake, even if that mistake is plainly visible; they consider mistaken creations more improbable and unique. “In all these cases, I’m mapping the conditions under which we might find value in the mistake.”

For companies that sell their products online, the latest research could provide a valuable  insight, since reviews are a more powerful motivator of purchases than even product discounts. Promoting reviews that mention a previous purchase mistake is a simple marketing trick. “It’s free, too,” Reich says, which makes it especially beneficial for companies that don’t have vast resources at their disposal.

Simple, free—but contrary to conventional wisdom. In a survey conducted by Reich and Maglio, 155 marketing professionals with an average of 13 years experience considered reviews without a mistake to be more effective than reviews that admitted to a mistake. 

“Marketers who are trying to persuade consumers are omitting from their work one of the things that helps them,” Reich says. “We have the empirical case for it, and yet people on the ground don’t know it and don’t use it. They need to be informed.”