Amazon's (AMZN 0.14%) Prime Day -- stretching across July 15 and 16 -- was a major hit. Sales were higher than any other shopping event in the company's history, the e-commerce specialist announced in a press release Wednesday morning.

Prime Day's success, of course, isn't a surprise. The members-only event, which lures in buyers with exclusive products and steep discounts, has been setting records ever since it first debuted in 2015. Still, continued momentum for the important event four years later is reassuring for investors betting on more strong growth in Amazon's e-commerce business.

A shopping cart icon on a smartphone

Image source: Getty Images.

Prime Day 2019: What you should know

Extending to 48 hours this year (up from 36 hours in 2018 and 30 hours in 2017), the shopping event lasted longer than it ever has. This undoubtedly played a key role in helping Amazon beat sales records.

But Amazon didn't just beat records -- it crushed them. Prime Day sales exceeded the company's Black Friday and Cyber Monday sales combined. This is impressive because Amazon announced last year that its 2018 Cyber Monday was its "single biggest shopping day in the company's history with more products ordered worldwide than any other day." 

Members purchased over 175 million items during Prime Day 2019, up from "more than 100 million products" during Prime Day 2018. 

The company also said it sold more Amazon devices during Prime Day 2019 than any other shopping event ever "when comparing two-day periods." The top-selling Amazon devices during the event were "Echo Dot, Fire TV Stick with Alexa Voice Remote, and Fire TV Stick 4K with Alexa Voice Remote," according to the press release.

Other key takeaways from Prime Day that Amazon shared on Wednesday include:

  • Member savings totaled over a billion dollars.
  • Millions of item were shipped and delivered within one day.
  • Eighteen countries participated in Prime Day -- double the countries of the first Prime Day.
  • This was the best Prime Day for both Fire tablets and Kindle devices.
  • Sales of Amazon's Alexa-enabled devices with screens were higher than they were for any other shopping event.
  • The company gained more new Prime members on July 15 than on any other day.
  • New memberships were almost as high on July 16 as they were on July 15.

A key catalyst

Given this broad-based strength in Amazon's Prime Day 2019, the shopping event will be a key catalyst for the company's third-quarter sales. To get an idea of Prime Day 2019's impact on Amazon's business, investors can look to the company's Q2 earnings release next week: In the quarterly update, Amazon will provide guidance for its third-quarter revenue. While Prime Day only accounts for a small portion of the quarter's duration, it has an outsize impact on sales.

Overall, investors should be pleased that the hype surrounding Amazon's Prime Day is still on the rise. And with so much momentum, this shopping event looks like it could serve as a key driver of Amazon's business for years to come.