Amazon recently enjoyed its biggest day of the year: Prime Day.With its unending parade of deals that rival the Black Friday sales following Thanksgiving, Prime Day was a huge event in 2016, and this year the bar went higher. The third annual sales event expanded to span 12 countries and to stretch the definition of a "day" by continuing for 30 hours. Sales grew by 60% compared to the previous year's event.New deals rolled out as often as every five minutes, beginning at 9 p.m. EST on July 10. Nearly 40% of the "lightning deals" were from small businesses and entrepreneurs selling on Amazon's marketplace.Amazon laid on its secret sauce, personalizing this year's experience and making deals easier to find by organizing them under 20 of the most-shopped-for themes for pet lovers, gardeners, techies, artists, etc. Alexa also was in the spotlight with deals on Amazon Echo, Echo Dot, Echo Show, Amazon Tap and compatible Fire devices. Current device owners, meanwhile, got access to Alexa-exclusive deals.Users of Amazon's mobile application received pop-up notices touting multiple "Pre-Prime Day Giveaways" from June 28 through July 10 that awarded products such as a 40-inch 4K TV.Other early bird deals included a four-month subscription to Amazon Music Unlimited for 99 cents; 40% off a Kindle unlimited membership, a 40% discount on a six-month Audible membership; and up to 35% off select Everyday Essentials products with onsite coupons. Amazon also pushed its Prime Video service by dangling $10 to shop on Amazon.com when a member streams a video included in Prime for the first time on her TV.Prime Day was created to reward and drive Prime membership. During the annual event, Amazon slashes prices on a wide assortment of items exclusively for Prime members. The first event in 2015 faced social media backlash for its largely comical assortment of obscure products with little mainstream appeal, but Amazon improved both the quality and quantity of dicounted merchandise the following year.Prime Day 2016 boasted global sales that eclipsed the first Prime Day event by more than 60% worldwide and 50% in the U.S. In addition to hawking the most Amazon devices in a single day, the retailer sold more than two million toys, more than a million pairs of shoes and more than 90,000 TVs that day. More than 14 million items were bought from third-party Marketplace sellers and small businesses. During the event, more than a million consumers accessed the Amazon app for the first time ever.This year, Amazon plugged several app functions to promote downloads. Users could preview upcoming deals and add them to a watch list to receive pop-up notifications when they went live. They also could add sale items to a bottom-of-the-screen list to easily compare the deals before checking out.In advance of this year's event, Amazon also dropped the price for a Prime membership from $10.99 a month or $99 annually to $5.99 a month for low-income consumers. To qualify initially, consumers need to produce cards used as part of the Supplemental Nutrition Assistance Program. The company also offers a discounted program for students."Every part of our business is working to deliver more deals for a record number of shoppers," vice president of Amazon Prime Greg Greely said in the release, which included a video showing the company's global Prime Day preparations.In addition to sales and new members, Prime Day provides Amazon with another benefit: data."Prime Day is another way to present customers with a cross-section of products from across their catalog," Jared Blank, senior vice president of data analysis at e-commerce marketing platform Bluecore, told Retail Dive. "Obviously, Amazon wants customers to buy from them. But they also want customers to browse, because they can turn that data into recommendations, which lead to more purchases down the road. Amazon is one of a handful of companies (Facebook and Netflix being two others) where the core infrastructure was built to turn customer data into a highly personalized customer experience. The more customers browse and purchase, the more they can customize what they present to you."Industry observers also note that other retailers can benefit from the halo effect of Prime Day."We've seen in the past two years that consumers are giving other retailers a chance to offer them Prime-like deals come mid-July. Knowing this, we believe that even brick-and-mortar retailers can easily bring in shoppers who are looking for highly-coveted merchandise at the best prices," said Paul Milner, marketing manager, Displaydata, in an emailed statement.