Porter's generic strategies captured the tension between cost and differentiation. Organisations normally operate with a higher cost base when they produce and sell a premium product that customers highly value. His model showed that differentiation is as effective a strategy as cost leadership.
No best strategy exists. Choosing a strategic position depends on time and circumstance. Implementation must be consistent once a position has been selected.
Porter based his model on Chandler's assumption that 'structure follows strategy'. Organisations require different sets of structural traits to accommodate either a low cost or a differentiation strategy. The selection of a generic strategy provides direction to management and staff that helps them acquire internal consistency between management style, reward system, recruiting policy, etc.