Align Product Type With Digit Type

Think of your product.

Perhaps it could be described as:

• Sharp
• Unique
• Precise

Well, those descriptions can also apply to digits. Strive for congruence when possible: Adjectives that describe your product should also describe your price.

Why It Works

• Congruence. Buying tickets to a concert? Since you want an emotional experience, you prefer discounts that are emotional (e.g., chance to win free tickets) because of this congruence (Chandon et al., 2000). Digits are merely a different medium to reach this alignment.
• Scaffolding of the Mind. All abstract ideas are built from primitive ideas that we learned early in life — e.g., spatial distance helped us learn numerical distance. These primitive ideas can add neural connections between two seemingly different domains (e.g., products and digits).

How to Apply

• Charge Round Prices For Round Products. In a pilot study, I alternated $9.37 and $10 for a knife and hammer. Participants significantly preferred $10 for hammer even though $9.37 was cheaper.
• Charge Round Prices for Networking Events. Customers who want social connectivity will prefer numerical connectivity (e.g., $50 is connected to many numbers). For example, participants were asked to rate the loneliness of each number from 1 to 100, and they attributed more loneliness to prime numbers that couldn't be divided. Same with prices: While comparing $19 and $21, lonely participants were less deterred by $21 because of its connections to 3 and 7 (Yan & Sengupta, 2021).

• Vary Your Digits to Convey Variety. Product variety seems higher when customers are exposed to more visual diversity (e.g., random shapes, types of people in ads; Khan et al., 2024). And I confirmed this effect in a pilot study: Repeating digits in a price reduced the perceived variety in a box of chocolates because people expected more repetition in the box.
• Charge Precise Prices For Analytical Tools. Customers preferred a calculator with a precise price of $39.72 or $40.29 (vs. $40; Wadhwa & Zhang, 2015). Though one study failed to replicate this effect (Harms et al., 2018). And I couldn't replicate a similar approach. I asked respondents to rate the accuracy of a kitchen scale, and I altered the precision of the price ($18, $19.73, $20, $21.73). But these varying levels of precision didn't influence the perceived accuracy of the scale.
• Charge Paired Digits For Paired Products. Would $7.88 convert better for a pair of socks? Similar effects happen with colors: Lonely customers prefer two colors that look similar because this visual companionship feels like social companionship (Kwon et al., 2024). Or maybe 88 can "feel right" for socks because the visual roundness of 8 resembles the shape of a sock. Perhaps 7 or 9 could deter customers because each digit has a visually sharp endpoint at the bottom.
• Charge Lucky Digits For Lucky Products. Prices in Singapore convert better with 8 because it's a lucky number (Westjohn et al., 2017). Perhaps this idea can explain why Western marketers love 7-ending prices. Or perhaps 7-ending prices convert better for products that require luck (e.g., lottery tickets, mystery boxes, trading cards).

Caveats

• More Research is Needed. This fundamental idea is widely supported, but the individual pricing applications need more empirical validation. I've been conducting a few pilot studies to test some of these effects, and I'll update this tactic with any successes or failures.
• Semantics vs. Visuals. Respondents preferred $10 for a hammer, but I'm not sure if this preference was due to shared roundness in the semantic idea or visual roundness of 0.

• Chandon, P., Wansink, B., & Laurent, G. (2000). A benefit congruency framework of sales promotion effectiveness. Journal of marketing, 64(4), 65-81.
• Harms, C., Genau, H. A., Meschede, C., & Beauducel, A. (2018). Does it actually feel right? A replication attempt of the rounded price effect. Royal Society open science, 5(4), 171127.
• Khan, U., Kim, S., Choi, S., & Labroo, A. (2024). Diversity Representations in Advertising: Enhancing Variety Perceptions and Brand Outcomes. Journal of Consumer Research, ucae060.
• Kwon, M., Jeon, E., & Han, Y. (2024). The social side of color: How social exclusion influences preferences for color combination. Psychology & Marketing.
• Schumacher, A., Goukens, C., Geyskens, K., & Nielsen, J. H. (2024). Revisiting surprise appeals: How surprise labeling curtails consumption. Journal of Consumer Psychology.
• Wadhwa, M., & Zhang, K. (2015). This number just feels right: The impact of roundedness of price numbers on product evaluations. Journal of Consumer Research, 41(5), 1172-1185.
• Wang, Y., Jiang, J., & Yang, Y. (2023). Magic odd numbers: The effect of numerical parity on variety-seeking. Journal of Retailing and Consumer Services, 73, 103345.
• Westjohn, S. A., Roschk, H., & Magnusson, P. (2017). Eastern versus western culture pricing strategy: Superstition, lucky numbers, and localization. Journal of International Marketing, 25(1), 72-90.
• Yan, D., & Sengupta, J. (2021). The effects of numerical divisibility on loneliness perceptions and consumer preferences. Journal of Consumer Research, 47(5), 755-771.