A research note on network effects: why a network's value grows roughly with the square of its users, why n log n is closer to the truth than n squared, the tipping point of critical mass, the adoption S-curve, and why all of it becomes a barrier to entry.
A research note on the build-versus-buy decision: the fixed-versus-recurring cost crossover that sets the break-even horizon, why cost alone never decides it, and the NUS LMS story as a worked case.
A research note on ergodicity: why a coin flip with a positive expected value still sends every individual player broke, the gap between the time average and the ensemble average, the volatility drag, and how this is the deeper why beneath the Kelly criterion.
A research note on marginal cost and economies of scale: why the hundredth unit costs less than the first, the difference between marginal and average cost, where the zero-marginal-cost economy comes from, the textbook U-shaped cost curve, and why rational decisions ignore sunk costs.