I still don't see how these have to be mutually exclusive. Fine, default to phone number since that's what most people are comfortable with, but it's not like t

I still don't see how these have to be mutually exclusive. Fine, default to phone number since that's what most people are comfortable with, but it's not like there's anything inherent making supporting alternative identifiers a difficult problem. Let it be my problem making my friends add my e-mail address to their contacts.