The problem is that kids under 13 years old are tipped off to the fact that Google does not want them using the site but nonetheless allows them to register because it does not ask them to verify their age.
When users create an email account, the terms of service state:
... you must be at least thirteen (13) years of age to Use this Service.Google then serves Gmail users a stream of advertising on Gmail and other Google sites that is supposed to be relevant to the person who logged in to check their mail. CARU said that Gmail was "the only major email Website that did not employ neutral age screening during the registration process."
A neutral screening process simply asks users for their age. If they enter an age that's too young, they are rejected. A non-neutral screen is one that names an age restriction and then asks for an age -- tipping off brats to enter bogus numbers. Google had neither system, but allowed kids to register anyway even though its own service terms alleged they didn't want kids.
CARU quoted Google as arguing:
Google maintained that the Gmail service was not directed to children and that the company did not have a reasonable expectation that a significant number of children under 13 would visit the site.Google said:
This was not an easy decision for Google because we have strong reservations about collecting user information that is otherwise unnecessary for providing Gmail services. Google does not target Gmail to children, nor do we ask users to provide a date â€" or even a year -- of birth.Google said it will employ a neutral screen to block anyone claiming to be under 13.