The way you write and display prices on an e-commerce site is more important than you may think. The way a price is written—its color, its placement in relation to the other elements of the interface—has a direct impact on the user experience and on sales. It comes down to a blend of UX writing and marketing.
We like to think that our decisions are rational and logical, but they’re not. Perception is a complex process that affects all areas of our life, including our purchases. Our decision to buy a product depends on many details that we’re not consciously aware of. A retail price seems more or less acceptable to us depending on many factors unrelated to the price itself.
Amazon’s product page
As UX writers, our main concern is what and how we write. Should we write numbers placing commas every third digit? Should we write decimals even if the price is a whole number?
There’s a widespread marketing strategy that states that prices should include decimals and end in .99. The main reason why marketing says that $27.99 is better than $28 is that we, Western people, read from left to right. When we see at first glance 27 instead of 28, we think that the price is lower than it really is.
Between 27.99 and 28 is exactly the same difference as between 27.98 and 27.99. However, we perceive a higher difference in the first case, because the number on the left changes. The main reason may be how we read, but it’s not so simple. It also has to do with biases that cause us to ignore, without realizing it, the cents.
The main bias behind this quirk is the anchoring bias. The anchoring bias explains that we focus on the first information we receive. We anchor our attention on the number on the left, rather than on the full price. Nielsen Norman Group has a good article on anchoring bias in relation to user experience.
The .99 trick is part of what marketing calls psychological pricing. However, UX is not marketing. We have to remember that many traditional marketing tactics are based on contradictory historical research conducted before the digital era, or even on myths that have never been proven.
While it is true that sales tend to increase when you use the .99 strategy, you have to take into account other details. In 2012, the Journal of Consumer Psychology published a study entitled Comma N’ cents in pricing that advises against using decimals in prices. Their theory is that we perceive numbers with fewer syllables as lower. If we omit useless commas, users may be more tempted to buy a product that costs just $6 (six dollars) than one that costs $5.99 (five dollars and ninety-nine cents). As I like to remind myself from time to time: KISS (keep it simple, stupid).
Our brain processes simple things more easily, so it’s not surprising that keeping things simple affects also higher numbers. $6 seems less than $6.00 and $1649 seems less than $1,649. When we delete the comma, we are less aware that the figure exceeds one thousand dollars. I have not seen this on many websites, but in Europe, we have a well-known example from one of the largest consumer electronics retailers. This screenshot is from a Spanish website, but they use the same trick in Germany, Italy, and other countries.
MediaMarkt’s product page
You may have noticed that this product page has another odd detail. The number is big and clear, but it does not include any currency sign. We assume, from the context, that the huge number is the price of the TV set, but there is nothing to indicate that 1649 is a price. Omitting the currency sign ($) and the name of the currency (Dollar) make us less aware that we are talking about money, and that pushes us to spend more money. I am not against all marketing strategies, but this particular one is problematic. Maybe you are not cheating the user, but you are being intentionally unclear. It’s cognitively ambiguous, so I would advise against it. We are UX writers, so clarity comes first and foremost.
If you work for a website or app that sells goods in several countries or languages, the issue with commas and periods in pricing becomes even more complex. Not all countries write numbers in the same way. In English, you would write 1,000 for one thousand and 1.00 for one dollar.
In most European languages, we use points and commas in the opposite way from English. That means that 1,000.00 in English translates into 1.000,00 in Spanish or French. It’s not a difficult change to understand and most language professionals are aware of it. But it can complicate design and development so be sure to plan for the differences.
In summary, how to write prices in e-commerce depends on several factors that may not always have the same answer:
If you’re not sure about something, you can always do some testing. UX is not an exact science; you need the feedback of your users. One last piece of advice about writing: always write
