Using your Canon ID to login to Canon’s digital camera software and apps will give you access to quick and easy product registration, tailored notifications about firmware, software updates, equipment notifications, new product announcements, and more to help optimize your experience with your Canon equipment.
So, ads? You'd figure the account would provide extra features (that we didn't need) but this doesn't even give anything to the user.
It's also possible there's a hidden max password size somewhere, like some fields only counting the first x characters of the password but it's inconsistent across different forms.