Pricing is based on the total number of customers that are in your ‘Customer’ tab in Shopify. Shopify and you; as the merchant control the ‘Customer’ tab.
Shopify will add any individual as a ‘customer’ if said individual has logged into your store, shared their email address, purchased something, etc. You can also delete and add customers in the ‘Customer’ tab to remove or add customers to the Fresh Credit app.
You cannot edit, add, or remove customers in the Fresh Credit app.