In an interview with The Wall Street Journal, Shin said the Galaxy S5 is selling at a faster rate than last year's Galaxy S4 phone. The Galaxy S4 sold about 10 million units in the same time frame after its launch.
Samsung, Apple, and other premium handset makers are under a lot of pressure to show smartphone sales growth. The high end of the smartphone market appears to be saturated, meaning the low end smartphone makers like Xiaomi are seeing rapid growth in emerging markets like China where customers are still making the transition from feature phones to smartphones.
Even though it's a record for Samsung, it's still a tiny launch compared to opening weekend sales of Apple's iPhone 5S. Although Apple doesn't break down iPhone sales by model, it did sell 9 million iPhones the weekend the 5S/5C launched.