When does a competitive advantage become a sustainable competitive advantage?

A sustainable competitive advantage is achieved when a company possesses attributes or resources that allow it to outperform competitors in the long run, leading to superior profitability over time. This typically occurs when other companies find it difficult or impossible to duplicate the value that the company provides, which is what makes option A the correct choice.

A competitive advantage becomes sustainable when it is not only effective in providing value but also resilient against imitation. This can arise from unique resources, proprietary technologies, strong brand identity, or customer loyalty that cannot be easily replicated by competitors. Therefore, a competitive advantage is termed sustainable when it contributes to long-term performance and is protected from the actions of rivals.

The other choices highlight concepts that may be relevant in different contexts but do not directly pertain to the definition of sustainability in competitive advantages. Collaboration can lead to strategic alliances but does not inherently create a sustainable advantage. Reducing a competitor's market share is a tactical move and does not guarantee ongoing superiority. Moreover, while market commonality and overlap can influence competitive dynamics, they do not inherently lead to sustainability unless they relate specifically to the uniqueness and irreplaceability of a company's value proposition.