The contribution margin concept is useful for deciding whether to allow a lower price in special pricing situations. If the contribution margin at a particular price point is excessively low or negative, it would be unwise to continue selling a product at that price. It is also useful for determining the profits that will arise from various sales levels (see the example). Further, the concept can be used to decide which of several products to sell if they use a common bottleneck resource, so that the product with the highest contribution margin is given preference.