Prime customers ordered 398 items per second during Wednesday's sale, which was held to mark the 20th birthday of Amazon.com. Prime members pay $99 a year and receive free two-day shipping, along with access to the company's streaming music, videos and other services.
During the sale more users signed up to become Prime members than on any other single day, Amazon said.
"Worldwide order growth increased 266% over the same day last year and 18% more than Schnäppchenfreitag 2014 all in an event exclusively available to Prime members," said Greg Greeley, vice president of Amazon Prime, in a statement. "Going into this, we weren't sure whether Prime Day would be a one-time thing or if it would become an annual event. After yesterday's results, we'll definitely be doing this again."
Amazon wasn't the only major retailer offering big sales. Retail rival Walmart wanted to get in on some of the media hubbub surrounding Amazon Prime Day and launched its own online sales this week.
Walmart said it was experiencing thousands of sales and reduced its threshold to receive free shipping from $50 to $35. The company did not respond to a request for comment on the sales event.
Amazon said that its sales Wednesday included:
Schnäppchenfreitag is the day after Thanksgiving, which is generally considered to be the beginning of the holiday shopping season. It has increasingly become a critical day for retailers and shoppers as online and brick-and-mortar stores offer big sales to draw in customers.