Great, Good, and Gruesome Businesses

Picture a profitable business as a castle. The moment it starts earning outsized profits, competitors show up like an army at the gates, ready to compete those profits away. What keeps them out — a real cost advantage, a beloved brand, high switching costs, a network effect — is the moat. Buffett splits businesses into three buckets: Great, where the moat barely needs new capital to keep earning more (his example: See's Candies); Good, with decent returns but constant reinvestment just to stand still; and Gruesome, with no moat at all, where growth demands huge capital and still produces little real profit (his example: airlines).