If you've ever wondered how to disable the shipping in your BigCommerce store, you will need to know that this is done automatically by the system every time the customer adds downloadable products to the cart.
I will show you an example from my test store - after adding to cart a mp3 song, there is no shipping estimator there:
Also, in the checkout process the customer will need to enter only the billing address:
Please be aware of the fact that when there is also a physical product in the cart, the system will enable the shipping again.