Let's say all consumers collectively eat X kg of ketchup per month. If 10% gets left on the bottle walls, they are buying 10% more, thus ~10% more profit for pr

Let's say all consumers collectively eat X kg of ketchup per month. If 10% gets left on the bottle walls, they are buying 10% more, thus ~10% more profit for producers. It works the same way we are using much more laundry detergent and toothpaste than necessary.