Marketing experts monitor the reactions of potential customers. It's marketing if both parties are trying to sell something to each other. Marketers are able to deftly stimulate demand, as well as manage it afterwards. In addition, marketers aim to influence the timing and composition of demand so that it is as effective as possible.

The negative demand is the total amount of goods that are not being demanded. This can be seen as a result of an overproduction or underconsumption. When the production of goods outweighs the demand for them, there are too many products to go around, so they cannot all be sold. The same thing occurs when people do not buy enough products or buy some other product instead of one or more of those being offered for sale.