I think the issue this, and all other identity systems have and will struggle with, is developer adoption. As a web developer, I'm not spending time adding thi

I think the issue this, and all other identity systems have and will struggle with, is developer adoption. As a web developer, I'm not spending time adding this to my site until a sufficiently high number of users are using. As it has no value beyond login itself, users will not adopt it. Because users have no adopted it, there's no reason for me to implement it. Because I have not implemented it, there's no reason of users to adopt it. Because… …you can see the problem. It's a neat idea, though.