More relevant information:
when i login the Arenanet site using my steam account, and then try to sign up for newsletters, i constantly get an error that prevents me from signing up... this error occurs when i type in an Email address and then press the "Sign Up" button. it says that "There was an Unspecified error. Please try again." every time i try. the FAQ does not address this.
Update: they finally sent me an email with a confirmation link. After clicking the confirmation link, it thanked me and said i was signed up. So look for an email. it may take a few minutes.