Amazon launched the 10th edition of its Prime Day shopping event on 8 July, extending the promotion to four days through 11 July and advertising “millions” of limited-time discounts for its more than 180 million global Prime members. The company is again mixing standard markdowns with fast-expiring Lightning Deals, while courting new customers with a 30-day free trial of its US$139-a-year membership. Rival retailers are aggressively counter-programming. Walmart’s “Deals 2025” sale runs until 13 July with price cuts of as much as 50 percent, Target’s “Circle Week” and Best Buy’s “Black Friday in July” end on 12 and 13 July respectively, and flash events at Wayfair, Nordstrom and others are offering similar double-digit discounts. The promotions aim to capture shoppers who either lack Prime memberships or prefer in-store pickup and broader product assortments. The cluster of overlapping campaigns underscores intensifying competition in US e-commerce and big-box retail. Analysts say the elongated discount window could erode margins but may also pull forward demand as consumers look to hedge against a newly announced 25 percent US tariff on imports from Japan and South Korea and the 145 percent duty already in force on Chinese goods. With inflation still elevated, retailers are betting that a midsummer price war will keep traffic and inventory turns high ahead of the back-to-school season.