This Is the Consumer’s Brain (and Wallet) on Amazon Prime Day

Buying a pillow-top mattress on Amazon.com seems like the most basic thing: Find, grab, check out, then wait for delivery (two days for Prime members). But behind that simple purchase lies a world of consumer decisions, emotions, expectations and habits, all interacting with external factors and influences. Layer on a sale, and a shopper’s brain exhibits still more complex behaviors. Make that heavily-promoted sale last longer than ever as consumers worry about tariffs — like Amazon just did with its recent four-day annual sale for Prime members — and the calculus of consumer spending gets super-intricate.

Just what nudged Amazon Prime shoppers this year from window shopping to clicking buy with their credit or debit card or using buy now, pay later (BNPL)?

PYMNTS Intelligence found that just over 1 in 2 — or 52% — of all adult American consumers purchased something during the event, a record number, spending an average $360, up 10% from last year’s two-day sale. For the first time, Amazon Prime Day this year lasted four days over July 8–11, not two (it went one day until 2017).

Most Prime Day shoppers bought items on days one and two. While sales lagged during the last two days, they were far from insignificant: Some 14% of Prime members made a purchase on the third day, and 8% on the last day, PYMNTS Intelligence found. Window-shopping via a mobile device or, less frequently, a computer, played a big role: 1 in 4 Prime shoppers browsed all four days, twice as many who window-shopped on only one day.

Changing Discounts

Some bargain-hunting shoppers likely noticed discounts fluctuating over four days. Dinesh Gauri, a marketing professor at the University at Buffalo’s School of Management, told PYMNTS Intelligence that it was “very likely” that Amazon’s use of price optimization and agentic artificial intelligence (AI)-based algorithmic pricing varied discounts on perhaps 5% to 10% of all sale products, depending on factors including product availability, popularity and manufacturer funding and through its $1 billion technology investment fund and for third-party vendors that make up 62% of all units sold through the global platform.

Reuben Sanchez of digital retail consulting firm Momentum Commerce in Boston, part of PMG, said in an email that “the urgency we had previously seen during day 2 (when it was the final day of the event) now shifted out to day 4.” What he called “the last-minute ‘empty the cart’ crowd” was responsible for “a good chunk of sales.”

‘Any Savings’

Clues lie in the field of behavioral psychology, which looks at how the human mind creates mental shortcuts and thinking patters, known as cognitive biases, that shape decisions that are seemingly irrational. Take the “anchoring bias,” when a shopper relies heavily on the first bit of information they see. Say a budget-conscious shopper spies a dress they like for $200, and then a second one they like for $100. That first price tag is “anchored” in their brain as a reference point, making the second dress seem like a steal and subsequent dresses with the lower price tag also automatically seem like a good deal — even if one or both dresses are overpriced or shoddily made.

Consumers worried about the impact of tariffs may have been thinking that their anchored frames of price references might soon be headed higher and that the discount was fine. A drop in a widely-watched consumer confidence index in June to 93 from 98.4 the month before signals that consumers expect tariffs to hurt the economy and to cause inflation, now 2.7%, to climb to 6%. If you’ve anchored to one price, think it’s eventually going to go higher, then any discount can seem good. Amid tariffs, “any savings offered by Amazon to consumers should have stimulated lots of purchases,” said Dinesh Gauri, a marketing professor at the University at Buffalo’s School of Management. At the same time, the event gave “extra time to think, plan and purchase items” without rushing, a move that increased its sales volume.

Amazon said shoppers scooped up discounted goods ranging from Apple AirPods Pro 2, BIODANCE Bio Collagen Real Deep Mask and Dawn Platinum Powerwash Dish Spray to Ring Battery Doorbells, Fire TV Stick HDs and half-price ice cream at Whole Foods. That suggests budget-minded consumers — nearly 7 in 10 now live paycheck to paycheck, PYMNTS Intelligence data shows — focused on smaller discretionary purchases.

Momentum Commerce, which helps businesses advertise on Amazon, said the average discount during this year’s Prime Day event fell 11% to 21.7% from 24.4% last year. Sanchez said that was likely a result of the Trump administration’s imports on low-cost imports from China, where Amazon sources more than 70% of its goods, according to one estimate. Though Amazon hasn’t yet announced how much it hauled in during the annual event, it declared it generated “record sales and savings” on brands including Dyson (vacuum cleaners and hairstyling tools) and Philips Sonicare (electric toothbrushes).

Now and Later

What’s known as the scarcity bias refers to the tendency by consumers to think that limits, whether on inventory or time frames, make something more valuable. Amazon taps into that via “lightning deals” that give shoppers 15 minutes to complete a purchase or lose the discount. What’s unique about Amazon Prime Day this year is how it prolonged urgency. “I think for a broad based retailer like Amazon, they create scarcity by many other means,” including the number of items in stock, varying discount percentages and offering price cuts on more items, Gauri said. Sanchez said that across four days, 25.6% of products on Amazon’s U.S. marketplace featured discounts, an 8% increase from 23.6% last year. And average discounts increased on each day — from 21.4% to 21.6% to 21.8% then 21.9% on the last day), suggesting the company added carrots to fuel buying momentum.

Neuroscientists have found that the typical sale triggers both loss aversion leading to buying, including fear of missing out (FOMO), and dopamine from the rush of the haul. Extend a sale for longer than ever and layer in celebrity influencers like LeBron James karaoke-singing Phil Collins, and Amazon had more time and ways to tap into the scarcity bias. “It’s just allowing ‘now’ to be a 4-day period,” said marketing professor Robert Schindler at Rutgers University’s School of Business.

Read more:

Amazon Says Customers Saved ‘Billions’ During Extended Prime Day

Tapped-Out Consumers Shape Summer Retail’s Innovation Bets and Price Wars

Shoppers Embrace Embedded Payments in Shift From Prime Day Splurging to Savings