Hm, looks like when you sign up for an account they auto-enroll you in their email lists, both for package tracking and for spam. It's not too hard to unenroll

Hm, looks like when you sign up for an account they auto-enroll you in their email lists, both for package tracking and for spam. It's not too hard to unenroll from the latter, but this sheds some light on why they'd be nudging people in the direction of account creation.