It's been clear for some time that Microsoft has lagged behind Sony when it comes to sales of modern consoles. However, it's been difficult to pin down the exact difference due to the paucity of public sales data. The best we've been able to do is report that, as of April, Sony had sold at least 7 million PlayStation 4 consoles through to consumers while Microsoft had sold just 5 million Xbox Ones to retailers. Today, Ars Technica took a stab at shedding more light on the topic in an interesting report that estimates Microsoft has sold no more than 7.5 million Xbox Ones worldwide since September, while Sony has sold at least a bit more than 10 million PlayStation 4 units