The function of a sales department is to engage in a variety of activities with the objective to promote the customer purchase of a product or the client engagement of a service, according to the American Marketing Organization. Some business management professionals consider sales an outgrowth of the marketing function, but others consider it an independent aspect of an enterprise's overall operational scheme, also according to the AMO.
No matter the exact technical definition of a sales department, as either an extension of the marketing apparatus or an independent entity, sales and marketing must operate in tandem. The cooperative, coordinated undertaking of sales and marketing functions ensures the realization of optimal revenue from customers or clients. Accordingly, a primary function of a sales department is coordinating its efforts to dovetail with those of the marketing department.
A sales department must develop and implement a protocol to sell a product or service that is suitable to the nature of that product or service while connecting it with prospective customers or clients. For example, some products or services require face-to-face interaction between a member of a sales team and a consumer to achieve a sale. Other products or services are readily sold online through a retail website or similar venue.