Darien,
I read that two ways. First I thought that it might mean that only someone like Andrewcx could get the referral bonus. (he
got an email from US Air.) But after reading it several times, I decided they meant that only someone whose email is typed on the web page can validate the referral. I.e. it can't be passed on to a 3rd email address.
I certainly admit see some ambiguity there.