Google just showed how serious it is about Cardboard

The joke seemed to be on Google when it passed out Cardboard, a virtual reality headset literally made of cardboard, at last year's IO conference. But today, the Google Glass maker showed it's quite serious about the headset by announcing updates for users, developers and makers alike. Oh, and it just happened to let slip that there are over half a million Cardboard "viewers," as it calls it, in people's hands.Google said it has been "working to improve" Cardboard ever since