23 Ice Cream Demand By evaluating and quantifying the effects described for the ice cream demand example, you can do the following: forecast with some confidence how much ice cream you are likely to sell each month (and hence how much you should produce) make choices about when you should make a special promotion (to uplift an anticipated sales slump) estimate how much difference those promotions are likely to make identify when something unexpected occurred (such as an undiscovered competitor taking market share)