Which they can already do with accounts they most likely already have: Facebook, Google, Twitter, LinkedIN any OpenID provider... So the only potential benefit

Which they can already do with accounts they most likely already have: Facebook, Google, Twitter, LinkedIN any OpenID provider... So the only potential benefit of Persona is the privacy, and if a user doesn't care about that then it's just another account you have to worry about (i.e. the very problem it tries to solve). As it stands, Persona's problem is that it just reinvents the wheel with slightly different spokes when people already have wheels that they consider good enough.