Back when it launched, Windows 8 took six months before Microsoft was able to sell 100 Million licenses. In just one month, Windows 10 is three quarters of the way to that figure. Windows corporate VP Yusuf Mehdi tweeted this morning that Windows 10 is already on 75 Million devices and is growing every day. In fact, the Windows 10 store "has seen 6x more app downloads "per device than Windows 8." Impressive! Besides the Microsoft hype machine and the obvious quality and improvements of Windows 10 over Windows 8, there's one big reason why it's turning out this way: it doesn't hurt that Microsoft is giving it away for free. This was probably the smartest move Microsoft has made in a long while to "re-engage" consumers.