They attract clicks, imply authority, slow down reading, improve recall, screw with prices and generally have a lot more influence over readers than those innocent little digits would suggest. All of this being fascinating fodder for a writer who wants to understand the mechanics of how readers interact with web writing.
At a Glance
Numbers affect how people scan, understand, remember and respond to writing online. Research suggests numbered headlines can attract more clicks, relatively small list numbers often perform well, precise numbers can command more attention, round numbers can be easier to remember, and long numerals are substantially harder to read than words. Even the difference between $9.99 and $10.00 can change how a price is perceived. For writers, the lesson is pretty simple: a number isn’t just information. How you present it is part of the writing.
Numbers are supposed to be the sober part of writing. Facts. Measurements. Prices. Statistics. The grown-ups in the room. Unfortunately, numbers are every bit as psychologically manipulative as words. Put one in a headline and people may be more likely to click it. Make it oddly precise and they may pay more attention. Round it off and they may remember it better. Knock a penny off a price and otherwise functional adults may perceive it as considerably cheaper. Who knew?
And yeah, there’s a reason this article has the title it does, and lists nine items. Let’s learn why.
1. Do numbers in headlines really attract more clicks?
Yes, numbered headlines can outperform otherwise similar headlines without numbers, although there’s no particular number guaranteed to increase clicks. There’s a reason the internet is full of headlines like 7 Ways to Write a Better Landing Page rather than Some Thoughts Concerning Landing Pages. One promises a defined amount of useful information. The other sounds like something written by a Victorian rector.
Outbrain’s research into headline performance found that headlines with numbers received higher click-through rates and pageviews. That’s not really surprising. A number makes an otherwise vague headline specific. If I promise you “ways to improve your writing,” you have no idea what awaits you. Three suggestions? Thirty-seven? A 9,000-word manifesto? If I promise nine, you know the size of the transaction before you click. That matters online, where every click is, if you think about it, a micronegotiation about sombody’s time.
There’s a visual advantage, too. Ways to Improve Your Writing looks different from 9 Ways to Improve Your Writing because the numeral interrupts a line of letters and gives the eye something else to grab. That’s an extremely small typographical flourish doing an impressive amount of work.
I’ve always preached using a 7 or 11 in a title, but it looks like I may have let an affinity for craps influence my thinking.
2. Do odd numbers get more clicks than even numbers?
Some headline research has found an advantage for odd numbers, but larger studies don’t support treating them as universally superior. This is one of those content-marketing facts that’s been repeated so many times it’s acquired the sheen of scripture: odd numbers outperform even numbers.
There is evidence for it. Outbrain reports that headlines containing odd numbers produced 20% higher click-through rates than headlines containing even numbers. Maybe 7 Ways to Improve Your Writing really does have an edge over 8 Ways to Improve Your Writing.
Why would it? Nobody knows for certain. Odd numbers may feel less manufactured, as though the writer stopped when the useful ideas ran out instead of padding the list to reach a nice symmetrical 10. That’s sort of the feeling I get when drafting a listicle, frankly; let’s leave it very slightly open-ended. Seven also carries a ridiculous amount of cultural baggage: seven days, seven wonders, seven deadly sins, seven dwarfs, the craps thing. Before we declare 7 the official integer of content marketing, though, there’s a problem. A much larger study disagrees.
3. Is 7 really the best number for a headline?
No. There’s no compelling evidence that 7 is the universally best-performing headline number. In one enormous headline analysis, 10 came out on top. BuzzSumo analyzed 100 million headlines to spy out which characteristics generated the most social engagement. Numbers from 3 through 10 did particularly well, with 10 performing best. More importantly, the data showed no strong preference for odd numbers over even ones. Of the top 20 numbers, nine were odd and 11 were even. So much for numerological certainty.
What probably matters more is what the number tells a prospective reader about the content. 3 things sounds quick. 7 things sounds substantial but manageable. 10 things suggests something reasonably complete. 47 things sounds like you’ve mistaken the reader for an intern with time on their hands. What, isn’t there coffee to be fetched?
Huge numbers have their place. “101 Writing Prompts” makes a different promise from “5 Writing Prompts.” The former is selling comprehensiveness; the latter is offering curation. For ordinary web content, though, relatively small numbers occupy a useful psychological middle ground. There’s enough there to make clicking worthwhile, just not enough to ruin lunch.
4. Do precise numbers make writing seem more credible?
Precise numbers can signal that a quantity was actually measured rather than casually estimated, although exactitude only helps when readers have reason to believe it means something. Consider Traffic increased about 30% and Traffic increased 27.3%. Which sounds as though somebody really looked at the analytics?
In their study “The Power of Precise Numbers: A Conversational Logic Analysis”, researchers Y. Charles Zhang and Norbert Schwarz found that precise numbers exerted a stronger influence on subsequent estimates than round numbers under the right circumstances. The effect depended on the precision seeming relevant and coming from a human communicator. Readers, in other words, tend to assume there’s a reason you bothered to be that specific.
If I tell you there were “about 400 people” at an event, I could be estimating. If I tell you there were 413, you’re likely to assume somebody counted them. That’s useful in writing. Most users preferred the new version carries considerably less evidentiary weight than 72% of users preferred the new version. Likewise, The campaign generated a large increase in leads is mush compared with The campaign increased leads 38%.
Precision does make an implicit promise, however. If you write 27.3%, you’d better know where the .3 came from. A suspiciously precise unsupported statistic isn’t evidence. It’s bullshit with a decimal point.
5. Are round numbers easier to remember?
Research suggests that rounding numbers can help readers remember their approximate values more accurately. Which nicely complicates all that advice about being precise, right?
Researchers Huy Anh Nguyen, Jake Hofman and Daniel G. Goldstein tested this in a preregistered randomized experiment reported at CHI 2022, “Round Numbers Can Sharpen Cognition.” Participants read news stories containing either precise or rounded versions of numbers. Counterintuitively, readers who saw rounded numbers were better at approximating the actual precise values later. The people given supposedly more informative figures did worse.
That’s worth remembering because writers tend to assume that more precision automatically means better communication. Consider The company generated $2,873,492 in revenue versus The company generated about $2.9 million in revenue. The first makes sense in a financial statement. If you’re simply trying to communicate the scale of the business, $2.9 million is probably doing more useful work. There are fewer grey cells being taxed for the reader, so maybe that contributes.
The decision comes down to what the reader needs from the number. Sometimes the exact figure is the information. Sometimes all those extra digits are getting between the reader and the point.
6. Are numbers actually harder to read than words?
Yes, particularly as they get longer. Eye-tracking research shows that reading long numerals requires substantially more eye movements and fixations than reading similarly sized words. That’s a good point to keep in mind if you write about finance, technology, research or anything else with a habit of spraying statistics hither and yon.
In a 2023 Acta Psychologica study called “Reading Numbers Is Harder Than Reading Words: An Eye-Tracking Study,” researchers recorded adults reading numerals, words and pseudowords. For short numerals, readers made about 2.5 times more fixations than they did reading similarly sized words. With long numerals, they made up to seven times more fixations and up to nine times more saccades, the rapid eye movements we make while reading.
So $2,783,492 isn’t simply seven digits plus punctuation. It’s a small cognitive speed bump. $2.8 million is considerably easier to absorb, assuming those missing $16,508 aren’t germane to the story.
This’s important online because readers aren’t known for approaching web copy with the meditative patience of medieval monks. They scan. A paragraph loaded with dates, percentages, dollar amounts, ratios and eight-digit figures may be technically readable while being functionally miserable. Numbers are useful. A wall of numbers can be as alluring as a spreadsheet. Apologies to any of you who are hypnotized by spreadsheets, but…
7. Can precise numbers make readers pay more attention?
They can. An unusually specific figure can suggest that the writer deliberately chose that level of detail rather than simply estimating. This is where the precise-number research gets particularly useful for case studies, research findings, sales results, performance claims and data-driven articles.
Zhang and Schwarz’s research into precise numbers found that precision influenced people’s judgments when they believed the specificity was relevant. A figure like 31.7% carries information beyond the quantity itself because it implies measurement. Consider the difference between How We Increased Conversion by About 30% and How We Increased Conversion by 31.7%. The latter invites a question: why 31.7? Presumably, somebody measured it.
That implication disappears if the statistic smells invented. 87.4% of writers will find this tip useful doesn’t become convincing because I fabricated it to one decimal place. Specificity works when readers infer that there’s a reason for it. Give them one.
8. Why does $9.99 still seem cheaper than $10?
One reason is the left-digit effect: when a price crosses a whole-number boundary, changing the leftmost digit can disproportionately affect how cheap or expensive the price feels. Everybody knows $9.99 is basically $10. Retailers are also aware that everybody knows this. They keep doing it anyway because the effect hasn’t gone away.
Researchers Manoj Thomas and Vicki Morwitz examined the phenomenon in their Journal of Consumer Research paper “Penny Wise and Pound Foolish: The Left-Digit Effect in Price Cognition.” Across five experiments, they found that nine-ending prices could be perceived as smaller than prices just one cent higher when that penny also changed the leftmost digit, as with $2.99 versus $3.00.
The interesting part for writers isn’t really the number 9. It’s that the presentation of a number can alter our perception of the underlying quantity. Mathematically, $9.99 and $10 are almost identical. Psychologically? They don’t necessarily land that way.
If you’re writing landing pages, ecommerce copy, promotional emails or product comparisons, that’s hardly an academic distinction. It’s literally money. Well, technically, one cent’s worth. But it can make all the difference in whether somebody buys.
9. Why does numbering information make it easier to read?
Numbered structures give readers visible information architecture. They indicate how much is coming, where the reader currently is and roughly how long it will be before the writer shuts up.
Consider the sentence There are three reasons this matters. Before you’ve encountered any of the reasons, you already understand the architecture of the argument. There are three components, you’re at the beginning, and after the third the writer has an implied obligation to move on. Numbering gives readers a kind of cognitive wayfinding by turning continuous information into discrete units.
That’s useful in articles, presentations, proposals and sales copy, especially when the subject is complicated. Writers sometimes resist numbered structures because listicles have spent the past 20 years making them look intellectually suspect.
That’s unfortunate. Numbering is simply information architecture. Three clearly identified reasons are easier to navigate than three unannounced paragraphs that happen to contain three reasons.
The listicle didn’t invent that. It just monetized it. That’s this listicle writer’s defence of sticking with listicles.
So how should writers use numbers online?
Use numbers when they clarify a promise, quantify evidence, simplify complicated information or give the reader useful structure. The obvious conclusion from all this would be to start cramming numerals into everything. Please don’t. Numbers work because they’re distinctive. If every headline becomes “7 Ways,” every case study contains six decimals and every paragraph has four percentages in it, you’ve turned a useful signal into wallpaper.
A few practical rules emerge from the research:
- Use numerals in headlines when the quantity itself is useful information.
- Don’t assume 7 is magically superior. The evidence is mixed, and BuzzSumo’s 100-million-headline analysis actually puts 10 on top.
- Keep ordinary lists reasonably short. Numbers from 3 through 10 performed particularly well in BuzzSumo’s headline research.
- Use precise numbers when the exact measurement adds meaning or credibility.
- Round numbers when readers primarily need to understand and remember the scale.
- Simplify long numerals when the exact figure isn’t important.
- Don’t bury prose in statistics. Long numerals require considerably more visual processing than words.
- Use numbered structures when they make complicated information easier to navigate.
- Never invent specificity. “63.7%” is not more credible when it came directly out of your ass.
Numbers aren’t decoration. They influence what readers notice, believe, remember and do. Writers should pay more attention to them, especially in writing for the web.
There are at least nine reasons.
FAQs about using numbers in writing
Do numbers in headlines increase clicks?
They can. Headline research from Outbrain found that numbered headlines generated higher click-through rates and pageviews. Numbers make a headline specific, visually distinctive and easier for readers to evaluate quickly.
Are odd numbers better in headlines?
Sometimes, but the evidence is mixed. Outbrain has reported a 20% click-through advantage for odd-number headlines. However, BuzzSumo’s analysis of 100 million headlines found no strong preference for odd versus even numbers.
Is 7 the best number to use in a headline?
No universal best number has been set in stone yet. BuzzSumo found that 10 generated the most engagement in its analysis, while numbers from 3 through 10 generally performed well. Seven may be effective, but there’s not enough basis for treating it as a magic number.
Why do numbers work in headlines?
Numbers make a headline more specific and tell readers roughly how much information to expect. They also suggest that the content has a defined structure, plus numerals stand out visually when surrounded by words.
Should writers use exact numbers or round numbers?
It depends on what the number needs to accomplish. Precise figures can imply measurement and evidentiary support. Rounded figures can be easier to process and remember. Exact numbers make sense when precision matters; rounding is often preferable when the reader mainly needs to understand scale.
Are numbers harder to read than words?
Yes, particularly long numbers. A 2023 eye-tracking study found that adults made substantially more fixations and eye movements while reading numerals than similarly sized words. The effect became much stronger as the numerals grew longer.
Why does $9.99 seem cheaper than $10?
One explanation is the left-digit effect. Research has shown that nine-ending prices can seem disproportionately lower when the price difference also changes the leftmost digit, such as $2.99 versus $3.00.
Sources and further reading
BuzzSumo: 100m Articles Analyzed: What You Need to Write the Best Headlines
Outbrain: How to Write Viral Headlines
Outbrain: 5 Content Marketing Tips to Boost CRO
Zhang & Schwarz, Journal of Experimental Social Psychology: The Power of Precise Numbers: A Conversational Logic Analysis
Nguyen, Hofman & Goldstein, Microsoft Research/CHI 2022: Round Numbers Can Sharpen Cognition
de Chambrier et al., Acta Psychologica: Reading Numbers Is Harder Than Reading Words: An Eye-Tracking Study
Thomas & Morwitz, Journal of Consumer Research: Penny Wise and Pound Foolish: The Left-Digit Effect in Price Cognition