There are various factors through which the demand of a product or a service can be reduced because of shortage in supply or to combat over-demand. One of the techniques through which demand can be reduced is through demarketing. In Demarketing, consumers are discouraged for the use of a specific product or service like in India, IPCL sells it's products and at the same time it promotes "Save Oil,Save India".
The basic concept of Demarketing is Deflating demand when the supply is short. Its new use is for differentiation. And is used when product improvements is not cost effective. You can find more details see this great link from Blurtit: