Channel members can do some things more efficiently than producers because they have built good relationships with their customers. These members have been able to help to overcome discrepancies that can appear where firms work together to bring a product to market. The quantity produced to achieve low unit costs has created a $,$ which is the difference between the amount of product produced and the amount an end$-$user wants to buy. A occurs when a consumer does not have all the items needed to receive full satisfaction from a product. A is created when a product is produced but a consumer is not ready to buy it$.$ because mass production requires many potential buyers, markets are usually scattered over large geographic regions, creating a $.$