Why on forms online are we always asked to type in our email address twice? It’s not usually encoded like a password usually is, so it’s not like we can’t see it as we’re typing the first time. If we screw up, we go and fix it, that simple!
I think at some point in the early evolution of Web commerce, someone got in the habit of thinking of email addresses similarly to passwords. I guess these are the guys who gave us the Y2K bug … or the Y2K scare, one or the other … or both, more likely!