Over 5m Google Cardboard devices have been shipped

"A year and a half ago we introduced Google Cardboard, a simple cardboard viewer that anyone can use to experience mobile virtual reality (VR). With just Cardboard and the smartphone in your pocket, you can travel to faraway places and visit imagined worlds. Since then everyone from droid lovers and Sunday edition subscribers, to big kids and grandmas have been able to enjoy VR—often for the very first time. Here's a look at where we are, 19 months in:
1. 5 million Cardboard fans have joined the fold.
2. In just the past two months (October-December), you launched into 10 million more immersive app experiences:
3. Out of 1,000+ Cardboard apps on Google Play, one of your favorites got you screaming “aaaaaaahwsome,” while another “gave you goosebumps.”
4. You teleported to places far and wide, right from the comfort of YouTube.
5. Since we launched Cardboard Camera in December, you’ve captured more than 750,000 VR photos, letting you relive your favorite moments anytime, from anywhere."
Source:  Google Blog, 27th January 2016