There are three types of agencies involved with advertising: the full-service agency, limited-service agency, and in-house agency. A full-service agency is an advertising agency that provides the most complete range of services, including market research, media selection, copy development, artwork, and production. Limited-service agencies are advertising agencies that specialize in one aspect of the advertising process, such as providing creative services to develop the advertising copy, buying previously unpurchased media space, or providing Internet service (Kerin & Hartley, 2017). 
How does one go about picking whihc is best for our situation? 
Kerin, R. & Hartley, S. (2017). Marketing (13th ed.). Retrieved from The University of Phoenix eBook Collection database