Five Forces Model: Industry profitability depends on rivalry among existing competitors, threat of new entrants, threat of substitute products, bargaining power of suppliers, and bargaining power of buyers.
Three Generic Strategies: Cost Leadership, Differentiation, and Focus.
Emphasised that companies must choose a clear competitive position, as attempting to be 'stuck in the middle' leads to failure.
Why It Matters
Considered one of the most influential strategy books ever written.
Its frameworks are widely used in MBA programs and by large corporations for strategic planning.