Post-sale discounts: inclusion in taxable consideration depends on whether discount induces dealer's supply to the end customer. Where suppliers issue financial or commercial credit notes without reducing the original transaction value, recipients need not reverse Input Tax Credit; post-sale discounts that merely lower a dealer's sale price in independent principal-to-principal transactions are not consideration for inducement, whereas discounts linked to an agreement to supply to end customers at a reduced price must be included in overall consideration as inducement. GST applies when dealers render distinct promotional or other services under a contract specifying such services and consideration.