Samsung announced today that first-month sales of its Galaxy S8 and S8 Plus have reached 5 million units. Sales of the previous year’s Galaxy S7 and S7 Edge sold an estimated 7-9 million units in their initial launch month, while back in 2013 Samsung announced its Galaxy S4 sold 10 million in its first month, a "Peak Galaxy" the company has never actually managed to surpass.
Source: APPLE INSIDER