If you want to maintain brand consistency, you can have your landing page appear to be hosted on your own domain. Having your landing page consistent with your domain will contribute to brand recognition and customer trust.
You can set up a custom domain through the application for Landing Page only. To set up a custom domain for email, purchase the subscription you want and then send an email to customer care at email@example.com. A customer care representative will promptly be in contact with you to set it up.