First-Ever Four-Day Format Shows Evolution in Consumer Shopping Patterns

Momentum Commerce, a modern digital retail consultancy part of PMG, has released its final analysis of Amazon’s Prime Day 2025 extended shopping event. The analysis observed more than $750 million in Amazon U.S. transactions across hundreds of brand accounts during the four-day Prime Day 2025 event.

Extended Format Drives Overall Growth

The inaugural four-day Prime Day event delivered total sales growth of 4.9% compared to the combined performance of 2024’s two-day Prime Day and the two days immediately following. This growth validates Amazon’s strategic decision to extend the shopping event’s duration.

“This year’s Prime Day represented uncharted territory for brands and retailers alike,” said John Shea, Head of Commerce at PMG. “Between ongoing tariff uncertainties affecting supply chains, pricing plans and advertising budgets, and Amazon’s bold transition to an extended four-day format, brands had to remain incredibly nimble. The event came down to a dramatic finish, with savvy brands fine-tuning their promotional strategies until the final hours while consumers responded with significant purchasing activity in the closing stretch.”

Deal Activity Shows Strategic Shift

• Across the full four days of Prime Day 2025, 25.6% of products on Amazon US featured discounts, representing an 8% increase from 2024’s rate of  23.6%
• While more products were on sale, the average discount depth decreased to 21.7%, down 11% from a rate of 24.4% in 2024
• Deal activity showed careful orchestration throughout the event:
  • Discount breadth increased progressively from Day 1 (22.7%) to stabilize on Days 3 and 4 (26.7%)
  • Average discount depths grew incrementally each day (21.4%, 21.6%, 21.8%, 21.9%), suggesting retailers strategically deepened discounts to maintain momentum

“Prime Day 2025’s impact extended far beyond Amazon’s ecosystem,” commented Parks Blackwell, Vice President of Marketing and Client Development at PMG. “Our analysis showed significant growth not just on Amazon, but across the broader digital retail landscape as consumers embraced this expanded shopping window. The event’s success demonstrates how Prime Day has evolved from a single-retailer sale into a cultural force and transformative market-wide phenomenon.”

Methodology

Sales data is based on an index of data Momentum Commerce’s Velocity platform observes across hundreds of brands collectively doing over $7B in GMV on Amazon US annually. Across the Extended Prime Day Event in 2025, Momentum Commerce observed more than  $750 million in Amazon U.S. transactions.  

Discount data encompasses both Prime Day-specific deals and general promotional discounts across more than 30 million products on Amazon US according to Velocity, Momentum Commerce’s proprietary commerce platform.