Michael E. Porter

If the forces are intense, (..) almost no company earns attractive returns on investment.If the forces are benign, (..) many companies are profitable. P. 25

Competitive forces = the underlying drivers of profitability P.25

Understanding industry structure is also essential to effective strategic positioning P. 26

The strongest competitive force or forces determine the profitability of an industry and become the most important to strategy formulation. The most salient force, however, is not always obvious. P. 26

In essence, the job of the strategist is to understand and cope with competition. P. 25

The essence of strategy is choosing what not to do.

Understanding the competitive forces, and their underlying causes, reveals the roots of an industry__ current profitability while providing a framework for anticipating and influencing competition (and profitability) over time. P. 26