Free Goods in a Trade Promotion 
It is common practice in many industries that when you sell certain goods, you deliver other goods free of charge to the customer, or you do not charge the customer for a portion of the goods sold. These free goods can also be used for trade promotions.
Prerequisites
You have maintained the necessary Condition Maintenance Customizing in SAP ECC and downloaded it to SAP CRM, or have maintained it directly in SAP CRM.
You have maintained the necessary customizing for condition generation.
Take particular care to ensure that the selected planning profile group you chose for the planning of free goods is suitable, such as the planning profile group 4TPF.