Amazon's Prime Day was immensely successful this year. Sales went up 60 percent compared to last year as Amazon extended the length of the sale to 30 hours. The best-selling product across any category and manufacturer was the Amazon Echo Dot. The original, larger Echo was discounted by 50 percent price cut to $89.99, while the Dot dropped by $15, bringing it to $34.99, with corresponding discounts in other markets where Echo devices are sold. According to Amazon, seven times more Echo devices were bought this year than last year.