What is Advertising Elasticity Of Demand?

Legal Definition
Advertising elasticity of demand (or simply advertising elasticity, often shortened to AED) is an elasticity measuring the effect of an increase or decrease in advertising on a market. Although traditionally considered as being positively related, demand for the good that is subject of the advertising campaign can be inversely related to the amount spent if the advertising is negative.
-- Wikipedia
Legal Definition
The amount demand changes prices for goods and services. If the item costs less more are sold. It it cost more less are sold and the price goes up.