Take a moment and imagine you run a poultry farm. You invest money to buy chickens. You also pay for necessities like food, electricity, vaccinations, and shelter maintenance. Initially, you earn $1,000 per month from the farm. Gradually, you spend more money to expand the farm and purchase additional chickens. As a result, now your monthly revenue is $1,500. The more you invest in upgrading your farm and caring for the chickens, the more income they earn for your business. Therefore, the money spend in the upkeep of the farm and the chickens is not a sunk cost. It is an investment.