Big brands have long relied on catchy slogans to distinguish themselves from competitors, often making glowing claims that are impossible to verify. Marketers refer to this type of language as “puffery” — subjective praise designed to create positive impressions rather than communicate factual information. For decades, courts and regulators have generally treated puffery as harmless exaggeration, assuming that consumers recognise it as promotional language and largely ignore it when making purchasing decisions.

However, new research from the University of Missouri challenges that assumption. A study led by Michael Thomas, an assistant professor of marketing in the Robert J. Trulaske, Sr. College of Business, found that puffery can significantly influence consumer behaviour, even when unknown sellers use it without an established brand reputation. According to Thomas, the findings suggest that seemingly harmless descriptive language may quietly shape purchasing decisions more than previously believed.

“Courts assume reasonable consumers ignore this kind of language,” Thomas explained. “But when we looked at real decisions involving real money, we saw that these words were quietly doing a lot of work.” His research examined how subjective terms influence actual consumer choices rather than relying solely on surveys or laboratory experiments.

Studying puffery has historically been difficult because slogans and advertising language are often closely tied to well-known brands. When consumers see familiar phrases repeated over decades, researchers cannot easily determine whether the language itself is persuasive or whether the brand’s long-standing reputation drives consumer trust. To overcome this challenge, Thomas turned to Airbnb, whose constantly changing rental listings created a unique opportunity to isolate the impact of language.

Unlike traditional advertising campaigns, Airbnb hosts frequently revise property descriptions while the actual properties remain unchanged. Using data from more than 219,000 Airbnb listings, Thomas analysed how changes in wording affected booking rates over time. His study found that adding subjective terms such as “charming,” “cozy,” or “lovely” increased bookings by approximately 0.2%, an effect comparable to adding factual information about amenities or location details.

“At scale, we can observe small effects,” Thomas said. “When you see the same pattern across hundreds of thousands of listings, it tells you something meaningful is happening.” The results directly challenge the long-standing belief that puffery is essentially meaningless because consumers disregard it. Instead, the findings suggest that subjective praise can subtly shape perceptions and purchasing behaviour in measurable ways.

Importantly, the study found no evidence that consumers later regretted purchases influenced by puffery. Researchers examined Airbnb reviews and found no indication that guests who booked listings with more flattering language expressed greater dissatisfaction afterwards. Thomas noted that while some critics may worry puffery encourages poor purchasing decisions, the data did not support that concern.

To conduct the large-scale text analysis required for the study, Thomas used OpenAI’s ChatGPT to identify and classify subjective claims according to established legal definitions of puffery. Artificial intelligence allowed the research team to analyse language patterns across hundreds of thousands of listings — a task that would have been nearly impossible manually. The findings suggest that while objective details such as price, amenities and location remain essential, carefully chosen descriptive language may further increase consumer interest and demand.

More information: Michael Thomas et al, Does Puffery Sell? Evidence from Airbnb, Journal of Marketing Research. DOI: 10.1177/00222437261444259

Journal information: Journal of Marketing Research Provided by University of Missouri-Columbia