I haven't found documentation regarding how to have my Gear VR (or Rift) users sign up to an email list. I've seen a few examples in Oculus store where this was possible by simply ticking a check box saying 'I agree to get promo emails etc' (with some free in-app gifts offered in return), and without typing in my email or anything, pressing the sign up button was sufficient for the app to store my email address. Is this possible with Oculus Platform SDK (ie. get user email address upon his permission)? Where should I look for it?
