Two questions about App revenue share

[lullyable]

Hi, 

I have two questions about the app revenue share with Shopify.

1. When I have approval to charge merchants outside of the Shopify Billing API, how do I share the revenue with Shopify?

2. Let's say there is a customer that I have gained by myself (outside of shopify), Do I have to share the revenue with Shopify if I'm using Shopify's API? 

Thanks in advance.

[cameronsmith]

I'd also like to know