But the origins of this sales juggernaut trace back to a single executive’s vision and a pivotal pitch to Amazon’s founder, Jeff Bezos.

The genesis of Prime Day

In the early 2010s, Amazon’s international business was led by Diego Piacentini, a seasoned executive who had joined the company in 2000 after a successful career at Apple. As Amazon’s global footprint expanded, Piacentini was tasked with finding new ways to energize both customers and the company’s growing base of Prime members outside the U.S.

According to Brad Stone’s book “Amazon Unbound,” Piacentini was inspired by the explosive success of Alibaba’s Singles Day in China, which had quickly become the world’s largest online shopping event. So Piacentini pitched Jeff Bezos on Amazon having its own event, and Bezos was into it, thinking the primary goal would be to drive sales to Prime, the company’s subscription service.

After obtaining Bezos’s blessing, Amazon executives reportedly went back and forth on when to hold their event. But according to Stone’s book, Amazon leadership eventually opted not to go toe-to-toe with Alibaba’s Singles Day, which is held in November, and instead decided on having their own sale during the summer months, a traditionally slower time in retail. The logic there was customers would have enough money during the summer months since they weren’t doing all of their holiday shopping just yet, and that also meant there would be ample warehouse space.

Amazon Prime Day got the green light in January 2015, with the goal of launching on July 15 to coincide with Amazon’s 20th anniversary.

From ‘Project Piñata’ to ‘Christmas in July’

The internal codename for the Amazon Prime Day initiative was “Project Piñata.” Meagan Wulff Reibstein, a young product manager who spent seven years at Amazon before departing for a VP role at Zillow, was assigned to execute the plan. She traveled to Amazon’s international hubs—Tokyo, London, Paris, and Munich—to convince suppliers and partners to participate in the event.

The first Prime Day launched across nine countries, and the response was immediate. In Japan, the massive surge in traffic crashed the local website. Across Europe and the U.S., customers snapped up deals, even as some complained about limited inventory and underwhelming discounts.

Despite technical hiccups and mixed reviews, the numbers told a different story: 34.4 million items sold and 1.2 million new Prime members added in a single day. “It was Christmas in July quite frankly—a bigger day than Black Friday,” Amazon CFO Brian Olsavsky told investors on an earnings call the following week.

Amazon Prime Day has only grown since then. In its second year, Prime Day sales jumped by 60%. By 2019, Amazon expanded the event to be two days, and in 2025, the event now spans four days. It kicked off on Tuesday, July 8, and runs until Friday, July 11—a full 96 hours to take advantage of deals.

Prime Day has become a crucially important event for Amazon. Last year, consumers in 23 different countries purchased over 300 million items with an average order value approaching $60. Notably, 88% of all Prime Day consumers were Prime members, and 85% of customers had been Prime members for over a year. And people tend to buy lots of Amazon products, specifically: Last year, Prime Day shoppers bought more Amazon Fire Sticks than any other item.

For this story, Fortune used generative AI to help with an initial draft. An editor verified the accuracy of the information before publishing.