A study examined the changes in advertising agency personnel perceptions of media sales representatives in light of the developments in advertising and the mass media that occurred from 1950 to 1986. Data were collected from four previously conducted and published surveys, as well as a 1986 survey. The findings revealed that advertising agency personnel have decreased their perceptions of the usefulness and influence of media sales representatives in their media decisions. Also, the salesperson's role was perceived in more limited terms in 1986 than in 1950. Four factors that influenced these changes in perceptions were (1) the emergence of "marketing" as the predominant business philosophy, (2) the introduction of computers into media planning, (3) the growth of syndicated audience research services, and (4) the emergence of new communications technologies. Fifty-six footnotes are appended. (HOD)