Does anyone have or know of any research on whether a "confirm email
address" field is helpful or increases the number of valid email
addresses? I am suggesting to my client that they drop it, on the
assumption that most people would copy and paste the same email
address. (But I don't know if that's true, I only know that's what
This is in the context of a checkout, where the email address is good
to have but not mission-critical to the task.