Just use the remaining balance on the card the next time you shop, even if you are shopping at another different – affiliate – point of sale. You do not need to spend the amount on the card in one go. The receiver of the card may freely spend the value on the card at affiliated web shops and physical points of sale. In case you are not sure what to buy someone, you could given them a such a card.
A gift card is a card that represents a specified value.