I sell digital downloads through Gumroad, a US-based platform. I offer them as pay-what-you-want (including free), and some customers choose to pay. These payments are received by my GST-registered Australian Pty Ltd company, with Gumroad taking a platform fee and transferring the balance to me weekly.
The digital downloads are intended for Australian customers, and I reasonably believe most purchasers are in Australia, although I have no way to verify their location.
Given this setup, should the income I receive from Gumroad be treated as GST-free or GST-inclusive for Australian GST purposes?