Fortunately, the iteration cycle in a software business is fast (we don’t need to retool milling machines here), and from some approximately correct starting point we can converge on a final product, almost like successive guesses at the solution to an equation. The quicker we iterate, the more steps we can take in the direction of this mythical point of perfect fit. Each such step costs money in wages, server costs, and lost time. When that cash balance goes to zero, the game is over and we’ve lost.