Get the list of bonus products which the customer is allowed to choose
from for this discount. This list is configured by a merchant entering a
list of SKUs for the discount. Products which do not exist in the system,
or are offline, or are not assigned to a category in the site catalog are
filtered out. Unavailable (i.e. out-of-stock) products are NOT filtered
out. This allows merchants to display out-of-stock bonus products with
If a returned product is a master product, the customer is entitled to
choose from any variant. If the product is an option product, the
customer is entitled to choose any value for each option. Since the
promotions engine does not touch the value of the product option line
items, it is the responsibility of custom code to set option prices.
If the promotion is rule based, then this method will return an empty list.
A ProductSearchModel should be used to return the bonus products the
customer may choose from instead. See