The Comma Effect

13.07.2016 |

Episode #3 of the course Price psychology by Andy Luttrell


When I first learned about numbers (this was many years ago, I assure you), numbers with commas in them seemed like they were on such a higher level. 10? Got it. 550? I’m still with you. 1,000? I’m out!

Then, as I got older, it seemed like those commas were totally optional. “5,000” vs. “5000”? Both were fine. Finally, I was free of comma-ridden tyranny. (Then I went to Europe, where commas are used as decimal points—like $550,99—and it was back to square one).

But even though commas feel like an arbitrary and completely optional part of any number greater than 999, they still carry psychological weight. Commas can still change the way a number feels.

For example, do you think you’d be more likely to buy a $1200 computer or a $1,200 computer?

If you’re a rational human being, you’d correctly recognize that I gave you the same price twice. You count up the number of pennies, and it will be exactly the same number of pennies. That little comma, though, can be a powerful influence on price perception. It makes the price feel just a little bit larger—which people don’t like.

Across a few studies, researchers asked people to look at some products and their prices. These people would sit at a computer and see a picture of a sleek laptop or TV, and under the picture would be the price.

Sometimes that price would have a comma (e.g., $1,858) and sometimes it wouldn’t (e.g., $1858). In the study, everyone was just asked to remember the numbers as best they could, and later, they rated how big the prices seemed from “small” to “large.”

On average, the versions of prices that had commas in them appeared more expensive than the versions without commas. Something as simple as a tiny visual cue changed the way the price itself was perceived.

Why does this happen, exactly? Well, the researchers explained this effect in terms of “syllabic length.” This just means that prices that take longer to pronounce seem bigger.

When a price includes a comma, it emphasizes that it’s in the “thousands” and encourages people to pronounce it that way. So $1,858 is “one-thousand eight-hundred fifty-eight.” What a mouthful!

Without a comma, though, people are more likely to think about the price in terms of “hundreds” and pronounce it that way. In this case, $1858 is “eighteen-hundred fifty-eight.” Much better.

So if you’re a marketer dealing with high-price items, keep those commas out if you want your price to seem lower. And if you’re a consumer, perhaps force yourself to read prices the long way and then decide if you’re willing to buy.

For more fun examples of price psychology, check out my video: “Price Psychology and Online Marketing.”


Recommended book

“Hooked: How to Build Habit-Forming Products” by Nir Eyal


Share with friends