Prime Big Deal Days: Bigger Discounts, Not Necessarily Lower Prices

During Prime Big Deal Days, two-thirds of Amazon.com products (66.1%) hit their highest discount rate of the prior 30 days. Only 2.0% hit their lowest net price in that window,  and just 1.5% did both. For most products, the advertised deal was the biggest of the month, but shoppers didn’t pay less than they could have at some other point in those 30 days.

The obvious explanation is reference-price gaming. A seller raises the list or “was” price before the event, then discounts from that higher number. The percent off looks larger, but the final price stays flat or rises. Some sellers on the platform probably do this, and the gap between 66% and 2% aligns with that. But this explanation is potentially too simplistic, given the nuances associated with pricing strategy intersecting a higher inflationary environment.

The same pattern would show up if list prices were rising because costs were rising. This year, they have been.

• Prices have risen sharply this year. The OpenBrand September CPI report shows durable-goods prices up 4.4% from January through September. That is the highest year-to-date increase since at least 2020, compared with 3.0% over the same period in 2025.
• Recreation and electronics, Amazon’s biggest categories, rose the most. Recreation goods are up 9.3% year to date, with media players up 12.3%, headphones up 10.8% and sound bars up 8.8% (OpenBrand CPI).
• Costs are rising. The report notes that Section 301 tariffs went from 10% to 12.5% on July 24, with those costs being passed through to consumers. Apple also raised list prices in June and July, citing memory-chip costs (OpenBrand CPI).
• Promotions were already being cut back. Before the event, September discount frequency fell to 23.3% and average discount size fell to 18.4% (OpenBrand CPI).

When list prices are resetting upward because costs went up, a seller can offer its biggest discount of the month and still land above an earlier price, one set before the cost increase. In that case, the deep discount softens the price increase rather than cutting the price. Retailers get a visible event, protect margins under cost pressure, and shoppers still pay less than the new full price, just not less than last month.

The SKU-level work still in progress could tell these stories apart:

1. Short-term list-price bumps: list prices rise in the 1 to 2 weeks before the event and fall back afterward.
2. Lasting cost-driven resets: list prices rise and stay up, tracking category CPI and tariff exposure.

If the deal-size gap is largest in the categories with the most inflation, like recreation, that supports the cost-pressure story. If it shows up evenly across categories, including ones with little inflation like appliances (up 0.7% year to date), that points more to how sellers set up the discounts.

Prime Big Deal Days still looked like a promotion, with record discounts across most products. But because list prices have been rising all year, a record discount didn’t mean a record-low price. That’s partly a merchandising tactic and partly what an event looks like when costs and prices are moving up. The SKU-level data will show how much of each.