Sweeps ( A television ratings term)

What are "sweeps"?  Sweeps are time periods when television stations/networks typically schedule programming designed to attract a larger than usual audience.

Why?  Sweep period programming is designed to attract larger audiences who in turn are exposed to advertising commercial messages. Thus, when the ratings for the sweeps period are revealed, the TV station/network can charge its advertisers more money because more people watched.

When do sweeps occur?  Typically four times a year: the months of February, May, July and November.

"The Sweeps" -  Local Market Measurement

Several times each year, Nielsen Station Index (Nielsen Media Research's local market measurement service) collects demographic viewing data from sample homes in every one of the 210 television markets in the United States. Each home in the sample maintains a paper viewing diary for one week. Each household member writes down what programs they and their guests watch in their home during the course of that week.

The term "sweeps" has been around since the beginning of TV measurement. These measurement periods are called "sweeps" because Nielsen Media Research mails out diaries to certain households around the country, then collects and processes the diaries in a specific order. The diaries from the Northeast regions are processed first and then swept up around the country, from the South, to the Midwest and finally ending with the West. The standard sweep months include November, February, May and July of each year.

In some of the larger markets, there are as many as three additional months (October, January and March) during which diaries are used to provide viewer information. Standard reports based on the diary data are produced and issued regularly to clients. This viewing information is used by local television stations, cable systems, advertisers and their agencies to buy and sell commercial advertising as well as make programming decisions.   (Source: Nielsen Media )