One way that a firm can learn how to create more value for customers by using its business-level strategy is to ask them how it can do so. This implies trust and recommendation on both sides. Diversified firms, ones with multiple businesses competing in many industries and market segments,
develop business-level strategies for each of the business units. However, non-diversified firms that compete in a single market product develop only one business-level strategy. Every firm needs a business –level strategy, and diversified firms need multiple business-level strategies plus multiproduct strategy and an international strategy if they compete in more than a single country’s markets. A competitive advantage is said to be sustainable if it cannot be copied, substituted or eroded by the actions of rivals, and is not made redundant by developments in the environment. This can be achieved by finding a balance between competitive defendability and environmental consonance.