The Nielsen Corporation, self-referentially known as The Nielsen Company, and formerly known as ACNielsen or AC Nielsen, is a global marketing research firm, with worldwide headquarters in New York City, United States. Regional headquarters for North America are located in the Chicago suburb of Schaumburg, Illinois. As of May 2010, it is part of Nielsen Holdings.
This company was founded in 1923 in Chicago by Arthur C. Nielsen Sr. in order to give marketers reliable and objective information on the impact of marketing and sales programs. ACNielsen began expanding internationally in 1939, and now operates in more than 100 countries.
One of Nielsen's best known creations is the Nielsen ratings, an Audience measurement system that measures television, radio and newspaper audiences in their respective media markets. In 1950 they acquired the C. E. Hooper company and began attaching recording devices to a statistical sample of about 1,200 consumer television sets in the U.S. These devices used photographic film in mail-in cartridges to record the channels viewed by the consumer and thus determine audience size. Later they developed electronic methods of data collection and transmission. In 1996, Nielsen split off this part of its operations into a separate company called Nielsen Media Research (NMR), which operated as an independent company until it was acquired by Dutch conglomerate VNU in 1999.
Another market research tool is the Homescan program where sample members track and report all grocery and retail purchases, allowing purchasing patterns to be related to household demographics. Homescan covers several countries including Australia, Canada, the United Kingdom, and the United States. In 2004, ACNielsen chose the CipherLab CPT-8001 as its data collection terminal for the Homescan program throughout Asia