Record of your registration will be kept on file, for purposes of taxes, statistics-gathering, and as a service to you (you can ask us whether you've registered already, if you're the forgetful type, or you can get your registration code from us if you lose it). Kagi and PayPal have their own privacy if you care what they do with your personal information.
Your street address will never be used for marketing purposes or any unsolicited mail of any kind. We send all products electronically, so we only need it to help verify your payment.
Your e-mail address will be treated in the same manner, with the exception of our newsletter, which is arguably a marketing tool (although the main intention is to notify registered users of upgrades and new products as a service to them). We will respect your desire to opt out of that, and you will not be added in the first place if you check the "opt-out" radio button when you pay at Kagi. The newsletter is very low-traffic; expect a mailing once a month at the most, and typically less. We will only send you a message if we have good news to report, which usually means new features.
To be added to or removed from our newsletter, just fill out our subscription form. You do not need to be a registered user to receive our newsletter. Remove requests are guaranteed to be serviced before the next newsletter is sent out.
To change the email address we have on file for your registrations, just fill out our address change form. We don't need notifications regarding your change of postal address.