Discount, Free Product and Substitutions
Discount, Free Product and Subtitution are all about giving beter conditions to your customers, but they have different ways of achieving this.
Discount
Discount as in standard Dynamics 365 Business Central pricing engines applies on the sales line price. When a sales line reaches defined conditions (Quantity, Base Quantity, Gross Weight, Netweight, nber of parcels) then a discount calculation is fired. With the Advanced Price Management module you can then create multi-level discount as explained here.
Free Product
Free Product is basically made to manage a “buy 2 get 1 for free” principle. This would result in two sales lines. The original sales line containing the requested item and quantity. Then an additional sales line containing the free item and quantity. You can get more details on how to use Free Product here.
Substitution
Substitution is basically used when you want to offer a product that would replace another one for the same pricing conditions as the substituted item. This is a common scenario when selling consumer packaged goods to have for a promotional/season period to offer a more valueable item for the same condition as the standard one (example: a +50% volume conditioner at the price of the standard one).
With Substitution feature you don’t have to remember the reference of the promotional item. Customer just have to place its order as usual, then the Substitution feature will automatically replace with the promotional item an apply the price calculation defines for the standard item.
Unlike Discount or Free Item, Substitution will therefore modify the input sales line with changing the item No.
You can get more details on how to use Substitution here.