SEATTLE—At Amazon headquarters here, two floors of conference rooms are outfitted as war rooms, the better to absorb the crushing blow of 85 million Prime shoppers feverishly tapping on the best slow cooker deals.  

Prime Day (or Prime Day plus six hours) is almost here. The sale begins tonight at 7 p.m. MT.

What started as an experiment to shake-up the shopping doldrums of July, with perhaps a sprinkle of inspiration from Alibaba’s wildly successful Single’s Day, has turned into one of Amazon’s biggest sales days. 

Last year, analysts estimate Prime Day sales totaled between $500 million and $600 million, or 1.5% of its third quarter sales — compared with the $3.34 billion spent online by Americans this past Black Friday at retailers. Amazon (AMZN), which does not release sales figures for the event, said they surpassed the prior year’s Prime Day by more than 60% worldwide.

Read the full story at USA Today.

A piñata in the Amazon conference room where Prime Day coordinators gathered in 2015 to oversee the company’s first Prime Day sale. The original event was code-named piñata. (Photo: Elizabeth Weise)

A piñata in the Amazon conference room where Prime Day coordinators gathered in 2015 to oversee the company’s first Prime Day sale. The original event was code-named piñata. (Photo: Elizabeth Weise)