The legendary Nielsen ratings, devised in 1930 to measure the audience of radio programs and later adapted to television in 1950, was the brainchild of Arthur Nielsen who was a market analyst whose career began in the 1920s with brand advertising analysis. Celebrating 60 years as the method of determining what viewers see on TV and how much sponsors pay for a commercial message, the system is in the midst of redefining itself in the digital age.
Milton Berle's Texaco Star Theatre led Nielsen's first rating "book" in 1950. Uncle Miltie was quickly overtaken by CBS's Arthur Godfrey Show in 1951 and then I Love Lucy which led the television programs of the 4 networks of the day (NBC, CBS, ABC, and DuMont) for the next 3 years.
CBS leads all networks past or present with total number 1 shows in the Nielsen Ratings with I Love Lucy, Gunsmoke, and All in the Family winning several years each. 60 Minutes, The Beverly Hillbillies and Dallas also won numerous years. Overall, CBS has had 27 number one shows in their sixty year history of television ratings.
NBC, in spite of a head start in television, placed second with 19 number one shows in its history. Bonanza, one of the first regular color television programs, won top rated program for 3 years from 1965 to 1967. The Cosby Show was the leading network show for 4 years from 1986 to 1989. Sienfeld and ER also contributed to NBC's Hall of Fame with multiple wins.
ABC was on the air for 23 years before attaining its first number one show, Marcus Welby, M.D. Happy Days, LaVerne and Shirley, Dynasty, and Roseanne have each been the top TV rating getter for one year. However, ABC has claimed the top spot only 8 times in Nielsen history.
FOX Television Network began regular programming in 1986. It remained a 4th place network up until 2004 when American Idol was put on the schedule. This phenomenal youth oriented singing talent contest has won top show for 6 years running now, boosting FOX to 3rd place overall in the ratings race.
Traditionally, ratings are taken by metered sets which transmit actual channel selection to the Nielsen headquarters daily. For a more developed sample, some families are recruited to fill in diaries of daily viewing activity which are mailed in and then analyzed to determined the demographics (age, gender, race) of television viewers. In the past few years, digitally recorded programs that are seen on a delayed basis are also counted in the final tallies. "Books" are prepared in February, May and November to formally publish the number of viewers each program has. New methods of program delivery such as by cellular phone and Internet have spurred Nielsen to count these new viewers in their surveys. Networks and local stations use the data to determine their rates for commercial time.