The purchase of TV. advertising time is a highly specialized phase of the advertising business, particularly for large companies spending huge sums of money. Large advertisers that do a lot of TV. advertising generally use agency media specialists or specialized media buying services to arrange the media schedule and purchase TV time. Decisions have to be made regarding national or network versus local or spot purchases, selection of specific stations, sponsorship versus participation, different classes of time, and eppropriate programs. A number of options are available to advertisers that choose to use TV. as part of their media mix. They can purchase time in a variely of program formats that appeol to various types and sizes of audiences. They can purchase time on a national, regional, or local basis. Or they can sponsor an entire program, porticipote in the sponsorship, or use spot announcements during or between programs Match the various media concepts related to buying felevision time with their implications for advertisers or medla planners of various brands currently using T.V. as a medrum as part of their IMC