Because it's something that's unique to you, so when we store your made-up nickname
we can associate it with your email address. Rather than deal with the hassle of passwords,
we let you use your email address as your "password". It doesn't have to be real, but you shouldn't
use an email address that belongs to someone else, because if there's ever a question of
who owns the nickname, the person who responds to the email wins. We'll never sell your
email address or send you anything without your permission. We promise.