The classification of advertising agencies are, the first one is Full-Service Agencies which provides services that are directly related to advertising such as copywriting, artwork, production of advertisements, media planning etc. The advantage of this type is that, there is a centralization of responsibility and accountability, simplified co-ordination and administration of the total advertisement program is possible, there is a greater objectivity, there is sales-oriented creative work and there is long standing and infield experience. The next type is modular agencies which is a full service agency that sells its services on a piece meal basis. An advertiser may get the copy prepared by one agency and other services by some other agencies. Sometimes an advertiser may hire only media department, and to execute the program, use another agency. Next type of agency is mega agencies which started functioning by 1980’s. Here agencies worldwide merge with each other to serve their clients.