Round numbers like 50% are often treated with scepticism. Precise numbers like 48.2% are more believable. That’s the Precision Effect bias – our tendency to trust information that’s detailed and specific. Use it to increase credibility and conversion rates from your messaging.
Psychologist Michael Santos demonstrated this bias in an unlikely setting. Homeless peoples who asked for “any loose change” got little. But those who requested 17¢ or 35¢ got 60% more donations. The precision of their request made people take notice.
Shotton highlights that precise numbers have value beyond distinctiveness. They are judged to be more credible and trustworthy too. In The Illusion of Choice, he cites a 2006 study by Rutgers marketing professor Robert Schindler, which presented participants with mock ads for a hypothetical deodorant. When the ad claimed the product reduced perspiration by 50%, people rated it as less credible than an ad claiming either 47% or 53%. The precise figures, even though lower, increased perceived accuracy by 10% and overall credibility by 5%.
This effect arises because, in our daily experience, we associate individuals who speak precisely with confidence and true expertise. Whereas, those who give vague information or loose generalities appear less knowledgeable and trustworthy.
WHAT’S GOING ON HERE?
We all love a nice round number, especially one ending in zero or five. It’s simpler to remember and makes mental math a lot easier. When heating up a cup of coffee in the microwave, I bet most of us turn the dial to 30 seconds, rather than the recommended 27. It feels comfortable.
Yet, when it comes to assessing the credibility of information, we’re more likely to prefer precise numbers over round numbers. This is because our brains associate precision with rigor, effort, and truthfulness. When we see a specific figure, we subconsciously assume it’s based on real data, making it more objective and believable.
PUTTING IT TO THE B2B BUYER TEST
To investigate whether the level of detail and precision in marketing information influences B2B buyers’ preferences and their decision-making processes, the survey company recruited a sample of 500 B2B buyers across the USA, Europe, and APAC.
Participants were split into three equal groups and shown a media banner advert from a fictional cybersecurity brand called Cryptex Secure. Each advert featured a different business performance claim.
- Group 1 saw a claim that featured a rounded number (“Customers experience 40% faster threat resolution”)
- Group 2 saw a claim that featured a higher precise number. (“Customers experience 42.4% faster threat resolution”)
- Group 3 saw a claim that featured a lower precise number. (“Customers experience 36.6% faster threat resolution”)
The results clearly demonstrate the influence of Precision Effect bias on buyer perceptions and engagement.
38% of buyers exposed to a rounded number claim perceived it as credible. This increased to 48% when the claim used a high precise number, and further to 51% with a low precise number — that’s a 34.2% uplift in perceived reliability.
Ads featuring precise numbers also led to stronger perceptions of quality and trustworthiness compared to those with round numbers.
Interestingly, ads with lower precise numbers scored slightly higher in credibility (51%) than those with higher precise numbers (48%), even though the performance output was lower. This shows that the presence of precision matters more than the magnitude of the number.
The findings confirm that using precise numerical claims in marketing communications can enhance credibility and positively influence brand perception — particularly in terms of trust and quality.
In B2B marketing, precision goes beyond establishing brand credibility — it’s about cultivating perceived trust, a critical driver of buyer behaviour, especially in high-risk, high stake business environments. Buyers are more likely to trust “a 17.4% increase in conversion” than “a significant improvement” — even if the difference is marginal.
This subtle psychological cue signals confidence, accuracy, and authority, helping marketers cut through skepticism. In a landscape where trust is hard-won and easily lost, applying the Precision bias can enhance message believability and influence decision-making. It’s not just about sounding smart — it’s about being perceived as real and reliable. For marketers, leveraging this bias can mean the difference between being considered… or ignored.
Precision also makes your messages more memorable and differentiates you from vague competitors. “Used by 67.2% of UK procurement teams” is more likely to stick than “used by over 60% of UK procurement teams”.
APPLYING THE PRECISION EFFECT
Here are a few ideas for applying the Precision bias to marketing strategies or campaigns to strengthen brand trust and drive greater levels of buyer engagement and consideration.
‘The power of 27.3%’ social campaign
Take a notable business performance stat or a customer case-study result, i.e., “27.3% reduction in operating costs”, and launch a social campaign promoting the benefits and value of your solution or product. Use a LinkedIn carousel or a short 30-second video that translates the precise stat or result into a tangible commercial outcome that your buyers are KPI’ed on or care about — making it easier for the decision maker to visual the impact.
An example could be:
Slide 1: “27.3% reduction in operating costs”
Slide 2: “That’s £1.3M saved across 12 months”
Slide 3: “That’s 3 fewer suppliers. 2 fewer systems. 1 stronger P&L”
Slide 4: “That’s what our platform delivered for XCUSTOMER”
Slide 5: CTA: See the full story →
‘Every percent counts’ video series
Turn five of your strongest customer success stories into a short-form video series, each anchored by one exact business performance stat — like “41.7% less downtime” or “32.4% higher revenue growth”. In concise, recorded virtual interviews, customers explain the real-world impact of that single percentage: how it changed workflows, improved employee experience, or delivered measurable value to their own customers.
‘The exact advantage’ personalised microsites
Drive high-value accounts to a hyper-personalised microsite that highlights the precise, quantifiable business outcomes achieved by companies just like theirs. Instead of broad claims, use exact metrics — like “41.7% reduction in downtime” or “£18,740 saved in support fees annually” — to build trust and credibility.
Deepen the personalised experience with a dynamic ROI calculator that uses publicly available data (e.g., company size, industry benchmarks, revenue, employee count) to generate precise, predictive business outcomes that can be gained when using your solution or offering
Do you want to know more about how to convince and win new customers, just reach out to ulf@sfinxconsulting.se
The study and report are presented by Transmission, one of the major B2B agencies in the world, working in partnership with behavioural scientist Richard Shotton and global research agency NewtonX.
