Definitions for "Income effect"
That portion of the effect of price on quantity demanded that reflects the change in real income due to the price change. Contrasts with substitution effect.
an example of increasing customer demand
The change in the quantity demanded of good X due entirely to a change in the consumer's level of satisfaction, all prices being held constant. (MY)   reflects the change in the price of a commodity upon the demand for that commodity by changing the purchasing power of income available for expenditure.