The numbers are in and Amazon Prime Day was huge. Amazon says it saw its largest sales day ever during its two-day Prime Day sales event. The online retail giant announced its Prime members bought more than 375 million items and saved over $2.5-billion across the two day sale. Amazon said the first day of the event was the biggest sales day in its history. It added that Prime members saved more money than any other Prime Day event. Adobe Analytics reported the average money spent on an order during the event jumped nearly $2 from last year.