definition
strict definition
marketing agency
A company hired to direct advertising or publicity for a particular product, brand, or property.
A marketing agency is a company which is hired to handle advertising programs or publicity drives for a specific product, brand, or property.
The assignment concerns promotion of an identified subject. A company can act for a particular building even when its ordinary clients come from other industries.
A model maker or animation designer can supply promotional material without directing the advertising program. Those production tasks do not alone establish the agency role.