So this is only for mac/iphone users? That's not a large enough segment to warrant adding a sign in option for most sites. Would be nice if Mozilla had done something similar with Persona.
Something like 58% of site visits are from mobile browsers, and mobile Safari makes up over half of all mobile browsers. Of course, your mileage may vary, but that's a pretty large segment.
So its like 25% of Americans and much less everyone else. Plus you will be at the mercy of apple if they decide to remove your app, plus if you need an actual usable email, you have to ask for a second email. Sounds a bit confusing, they shouldnt have tied this to email address.
