Thank you for reaching out! That is correct, in order to be certified through the Advertising Cloud Academy, one must be an Advertising Cloud customer. This is because our in-person certification is a free, added-value option. In the future, we may be exploring an option where one could pay a course fee to attend.
If you're interested in staying up to date on our options, please e-mail the Academy (email@example.com) with your contact information so that we may keep you posted.
Please let us know if you have any other questions and we'd be happy to help!