Which of the following is NOT a key ingredient of a successful product?

Desirability, viability, and feasibility are fundamental components that contribute to the success of a product. Desirability focuses on whether users actually want the product, reflecting the importance of understanding user needs and preferences. Viability pertains to the product's potential to succeed in the market, ensuring there are sufficient customers and revenue possibilities. Feasibility relates to the practicality of developing and delivering the product within certain constraints, such as technology and resources.

While affordability can influence a product’s market acceptability, it is not considered a primary ingredient in defining a successful product in the same way the other three elements do. Affordability tends to be a broader market characteristic that can change based on economic conditions, target audience, and perceived value rather than a foundational aspect of product development. Therefore, it does not hold the same weight in defining product success as the other three critical factors do.