We collect email addresses from two sources. The first is a form on this website, which allows you to also specify your subject area interests. The second is the shopping cart. If you give an email address when purchasing from us, we will add you to our mailing list. If you wish to be excluded from such emails, simply use the unsubscribe link in any email you receive from us.
We strive to focus solely on subject areas that should interest you, in order to keep the frequency of emails low and relevancy high.