Did you hear? Amazon Prime Day is coming! It’s almost here! Two days of epic deals! More than one million products on sale! The robots are readying! Lady Gaga is headlining! Amazon Prime Day, for the uninitiated, is Amazon’s annual blow-out shopping event. Amazon first tried out Prime Day in July 2015, to mark its 20th birthday. The shopping holiday is a consummate American experience—think Black Friday, after-Christmas sales—and Amazon, two decades into the retail game, felt confident it could create one all its own. “Step Aside Black Friday – Meet Prime Day,” read Amazon’s press release introducing the event. The first Prime Day was a success, of course. Amazon was a giant—the giant—of online retail, and when it declared a shopping holiday, people paid attention. Over the past four years, Prime Day has grown from an Amazon-led festivity to summer’s biggest shopping event. Other retailers, eager or perhaps desperate to compete, have launched counter-programming, and in doing so legitimized Prime Day more than Amazon ever could. Read more at Quartz.