What do you call a product, service, or competency that adds value when combined with another offering?

The term that refers to a product, service, or competency which adds value when combined with another offering is a complement. Complements are products that enhance or increase the utility of another product. For instance, a printer is a complement to a computer because the printer's value is realized primarily when used alongside a computer, as it allows the user to print documents.

In strategic management, understanding complements is crucial for crafting competitive advantages and innovative strategies, as firms can create value chains that effectively utilize these relationships to enhance their offerings. For example, firms often pair products with complementary goods to create a more attractive package for consumers, which can lead to increased sales for both products.

Other terms do not capture the essence of this value-adding relationship as effectively. A supplement generally implies something that adds additional features or support but doesn't emphasize the synergistic relationship. An extension typically refers to new lines or versions of existing products, rather than highlighting the relationship with another product. An accessory generally adds functionality but may not significantly boost a primary product's value in the same synergistic way that complements do. Thus, in the context of strategic management, recognizing and utilizing complementary relationships can be a key strategy for enhancing value propositions.