Short answers, pulled from the story.
Nielsen Media Research began measuring television viewing habits in 1950. The company used a device called the Audimeter to record viewing habits onto 16mm film cartridges and mailed them weekly to headquarters in Evanston, Illinois.
Nielsen Media Research used four specific months for paper diaries known as sweeps: February, May, July, and November. The term sweeps dates from 1954 when Nielsen collected diaries from households in the Eastern United States first before sweeping west.
Nielsen Media Research introduced the People Meter system in 1987. This system recorded individual viewing habits and transmitted data nightly to Nielsen through a telephone line to allow minute-to-minute study of television viewing.
During the 2007-08 season, ABC was able to charge $419,000 per commercial sold during its medical drama Grey's Anatomy. This rate was significantly higher than the $248,000 charged for a commercial during CBS' CSI: Crime Scene Investigation.
Nielsen Media Research began compiling a weekly top 10 list of most-watched shows on streaming platforms in September 2020. The company announced Nielsen Streaming Video Ratings in 2021 to measure total viewership and audience demographics on streaming platforms.
Nielsen Media Research gained accreditation for its Big Data + Panel from the Media Rating Council in January 2025. This system combines traditional panel data with big data from smart TVs and other digital devices to track viewership across 45 million households.