An advertising agency is a company specializing in the management and sale of advertising space from one or more media to advertisers, on the basis of quantitative and qualitative studies of the audience. The contract between the medium and the control room can relate to all the advertising present in the medium or only a part defined according, for example, to the location of the broadcast (local or extra-local advertising), or to the type of advertising ( show, classifieds, legal information, etc.). The management is remunerated on the basis of a commission deducted from the price of advertising space. Through their management consultancy role, the agencies are at the origin of advertising linkages, the creation of sections, supplements, special editions and other attractants for advertisers.
With the digitization of advertising media, we are observing the emergence of specialized advertising network: Demand-side platform (DSP) or platform for purchasing and advertising optimization. This type of new management allows advertisers to improve their investment in real time and facilitate transactions, for example a website. These platforms generally use the RTB (Real Time Bidding) model, which is an auction of advertising space. More precisely, this platform can select the most favorable available media according to audience and price criteria defined by the buyer.