(a) Advertising agency is an independent service-rendering organization. It delivers various services and performs many functions for its clients, who are advertisers. It is mainly involved in activities like planning, preparing and placing of ads in media. It also performs non-advertising functions for them. It offers them advisory and creative services. It does so to make a profit. 

Functions : 

(i) Media selection : Advertising agency helps an advertiser to select a proper media (ad platform) to promote his advertisement effectively. Media selection is a highly specialized function of an ad agency. It must select the most suitable media for its client’s ad. It must choose media, which has a potential to give best results for the lowest cost. It must select more than one media for the ad. For example, an advertisement can be put on television, the internet, newspapers, magazines, etc. After selecting the media, the ad agency must maintain goods contacts with the media. 

(ii) Sales promotion : Advertising agency performs sales promotion. It helps an advertiser to introduce sales promotion measures for the dealers and consumers. This helps to increase the sales of the product.