Chopra identifies four sources of sustainable competitive advantage. Switching costs: once customers invest time, data, or workflows into your product, moving becomes expensive. Network effects: your product gets more valuable as more people use it. Cost advantage: you can produce or deliver at a lower cost than competitors. Quality advantage: you deliver a meaningfully better experience that justifies a price premium. The critical constraint he adds: you cannot compete on cost and quality simultaneously. Choosing both means being second at both. The defensible business is built on a clear choice between the two — and then relentlessly deepening that advantage rather than hedging across both. Do what is hard, because everyone is doing what is easy.