Sales outsourcing agencies typically work with businesses of all sizes, but they are often hired by small and medium-sized businesses that do not have the internal resources to support a full-time sales team. In many cases, these agencies will customize their services to meet the specific needs of their clients. The advantages of working with a sales outsourcing agency include access to a larger pool of potential customers, increased flexibility in terms of pricing and service offerings, and the ability to scale up or down as needed.