I hate that the best user experience for logins is "Login with facebook" or "Login with Google". I don't want to impose that privacy failure on my users, but I also don't want to impose the annoyance that is "Sign up with a username, email address, and password". Offering all of the options is also a compromise that complicates the user experience. Now, here's the sad thing, for me: I didn't even know Persona existed…
I know of an easy way to remove 33% of that ...
Email addresses are globally unique, and everyone already knows theirs ... email + password seems like a simple, well accepted and workable solution.
Right ?