Hi.  We are moving to deprecate the use of a separate entity for Prospect and Customer.  We consider being a prospect to be a state of a customer entity.  You might be a prospect today and become a customer tomorrow.  You can be a customer for one product and be a prospect for another product.  In the 1:1 customer centric world, maintaining a completely different entity for these makes less and less sense and so within NBA Designer, we only use the customer class.  If the state of the customer is important, you can have a property on the customer that indicates if they are a customer or a prospect.  Additionally for inbound channels that use container, you either not pass in a customer ID and a cookie would be dropped for this customer to identify them as a potential prospect (if Pega is managing identity for you) and if you are managing identity through a 3rd party, then you can pass in the identifier to the unknown profile as an ExternalID to the call to the container.