The concept of suggests that when a company has built significant value into its product offerings, trying to increase the value of the products by even a small amount requires a significant financial investment.

diminishing returns

Explanation:

I'll provide you with a situation as an example.

Let's say that you are running a successful ice cream company. Typically, ice creams are made with dairy. This made a certain percentage of population couldn't consume it since they are lactose intolerant. (Basically eating dairy will give them diarrhea ).

There are not many people who have this condition. Let's say that you want to increase the value of your product and use the materials that makes your product become consumable to this specific population while maintaining the original taste.

This would resulted in a small amount  increase in customers base , but the investment that you need to make in order to make it happen will be substantial. You basically have to invest in researches to find the perfect ingredients, invest in additional marketing expense to educate the customers on the new product, change your current production flow, etc.

answer; buying the bill at a discount from the face value to be received at maturity;