Bet they assumed Windows Phone contributing a few hundred million
Because they know the mobile market so well - after all they were so quick to recognize how the smartphone world was going to completely change the minute the iPhone was first shown.
Oh wait, that was Google's Android team that realized that; Microsoft continued to putting out the same tired stuff that looked and acted like it was designed in 2001 and thinking Blackberry was their competition.
The only thing that will let them EVER get to a billion devices is quitting selling Windows 7 and stopping updates for it in early 2020. Until that end date for Windows 7 forces enterprises to get serious about upgrading to Windows 10 in 2019, they won't reach a billion.
Biting the hand that feeds IT
