This article needs additional citations for verification. (August 2011) ( Learn how and when to remove this template message)
|Headquarters||85 Broad Street, New York City, New York, U.S.|
Nielsen Media Research (NMR) is an American firm that measures media audiences, including television, radio, theatre films (via the AMC Theatres MAP program) and newspapers. NMR, headquartered in New York City, is best known for the Nielsen ratings, an audience measurement system of television viewership that for years has been the deciding factor in canceling or renewing television shows by television networks. As of May 2012, it is part of Nielsen Holdings.
Nielsen Media Research, once one of the largest media research companies in the world, began as a division of ACNielsen, a marketing research firm. In 1996, Nielsen Media Research was split off into an independent company and in 1999, was purchased by the Dutch conglomerate VNU. In 2001, VNU also purchased ACNielsen, thereby bringing both companies under the same corporate umbrella.  VNU was reorganized and renamed the Nielsen Company in 2007.
The Nielsen TV Ratings have been produced in the USA since the 1950-51 television season and statistically measure which programs are watched by different segments of the population. The most well-known portion is the "diary". During the four " sweeps" months of February, May, July and November, Nielsen interviewers in Oldsmar, Florida and Radcliff, Kentucky ask homes to participate in filling out a diary of the programs watched in their home for a one-week period.
The Nielsen sample included roughly 1,700 audimeter homes and rotating board of nearly 850 diary respondents, by the early 1980s. Nielsen launched its Nielsen Homevideo Index (NHI) in 1980 to measure cable, pay cable, and VCRs, and the NHI began offering daily cable ratings in 1982. Nielsen’s continued to advance with steady changes into the mid 2000s (decade). Along with changing their counting methods, Nielsen also started emphasizing their sample in 2003 in reaction to census shifts and requests from some industry sectors. Nielsen’s automated Local People Meter (LPM) technology was introduced in New York and Los Angeles. The LPM improved the method of measurement from active and diary-based to passive and meter-monitored. More importantly, the LPM provides accurate measurements to particular local markets, verse a nationwide sample from the People meter. While diary-based surveys concentrated on quarterly sweeps periods, the industry has been pushed toward year-round measurement, due to the automated LPM system.
In 1996 Nielsen Media Research began tracking computer, internet, and video game usage through telephone surveys. 
Recently, Nielsen announced the launch of its A2M2 project that would measure television viewing in and out of the home.[ citation needed]
Nielsen Media Research is a sister company to Nielsen NetRatings, which measures Internet and digital media audiences through a telephone and internet survey, and Nielsen BuzzMetrics, which measures Consumer-Generated Media.
Nielsen also conducts market research for the film industry through National Research Group (NRG).
In September 2018, Nielsen acquired SuperData Research, a industry analysis firm that deals with tracking viewing habits within the video game and eSports areas, an area that Nielsen plans to expand into. 
The company maintains an office in Oldsmar, Florida. Most of the employees of Nielsen Media Research work in Oldsmar, and the company's media measurement work originates from the office. The Associated Press said that the Oldsmar building, with a cost figure of $80 million, was "its so-called nerve center."
Nielsen went in for an IPO ( NYSE: NLSN) in January 2011 and was the largest public offer in the United States in the previous four years. Being the largest IPO for a firm backed by private equity at $1.64 billion, the IPO was well received and closely watched by all big banks and private equity boutiques  On March 1, 2011 they announced the appointment of Liz Zale as Senior Vice President for Investor Relations. Liz Zale was previously Vice President for Investor Relations at Moody's Corporation ( NYSE: MCO). 
- FABRIKANT, GERALDINE (13 August 2011). "Big Makeover for Dutch Media Data Company". New York Times. Retrieved 1 August 2011.
- "Tidbits...". Electronic Gaming Monthly. Ziff Davis (82): 20. May 1996.
- Grubb, Jeff (September 5, 2018). "Nielsen acquires SuperData Research to better track digital games and esports". Venture Beat. Retrieved September 5, 2018.
- " Univision sues over Nielsen's meters." Associated Press at the St. Petersburg Times. June 11, 2004. Retrieved on August 28, 2011.
- " Contact Us Archived 2011-08-29 at the Wayback Machine.." Nielsen Holdings. Retrieved on August 28, 2011. "The Nielsen Company, 770 Broadway, New York, NY 10003-9595"
- Cowan, Lynn (26 January 2011). "Nielsen, Demand Media Jump on Debut". Wall Street Journal. Retrieved 4 April 2011.
- Bouryal, Kristie. "The Nielsen Company Appoints Liz Zale Senior Vice President for Investor Relations". Nielsen Press Room. The Nielsen Company. Archived from the original on 24 April 2011. Retrieved 4 April 2011.
- Lotz, Amanda D. "The Television Will be Revolutionized." New York University Press. Retrieved April 13, 2011.
- Stoddard Jr., Laurence R. “The History of People Meters: How We Got There (And Why).” United Kingdom, Cambridge University Press.