What Are Television Ratings?
Companies that advertise on television need to know how many viewers they are getting for the money they are spending on air-time. In order to accomplish this, viewers are surveyed and the survey results are called ratings. Ratings make or break a television show. No matter how critically acclaimed a program may be, if it doesn't have high enough ratings, it won't be able to draw enough advertisers to make it worth producing.
Ratings are also used to determine how much networks can charge for commercial time. Advertising prices are measured in "cost per thousand TV viewers" or the CPM. Networks will look at the ratings and the demographics of their viewers (their age, sex, and where they live) to determine a program's CPM. If the CPM is four dollars per minute, and rating surveys show an audience of two million viewers, the cost for a 60 second commercial is eight thousand dollars. Commercial time for highly-rated series, such as Friends, can cost upwards of a million dollars per minute, and one-time-only extravaganzas like the Super Bowl can bring in over one million dollars for a 30-second spot.
| Let's Make a Deal! The interesting thing about CPMs is that television advertising is sold long before a new show appears on the air. When they are creating new programming, network executives arrive at a cost for advertising by estimating the expected viewing audience based on the day and time slot, and the past performance of similar programs. (For example, a half hour sitcom at 9 pm that follows a highly popular show is likely to attract a good audience.) If a show gets more viewers than expected, this is a bonus for advertisers, who have paid for fewer viewers. If a show doesn't live up to expectations and doesn't attract the estimated viewing audience, then network executives would have to provide free advertising to make up for their loss. |
Nielsen Media Research tracks ratings in Canada and in the U.S. "Nielsen Families" are chosen at random and asked to volunteer their time free of charge. About 50 per cent of those approached agree to participate - some for up to five years. (In Canada, there are over 11.7 million television households, compared to over 97 million television households in the United States.)
In Canada, the Bureau of Broadcast Measurement (BBM) does the "Sweeps" ratings - surveys which "sweep" the country from coast to coast during the months of November and March to measure the numbers of viewers in local markets. Nielsen tracks the country during the rest of the year. The BBM surveys 80,000 viewers in 42 different markets during the "Sweeps," by asking families to record their television viewing in a diary. Nielsen, which estimates national averages by monitoring the viewing habits of 6,150 Canadians, uses two types of electronic devices to track viewing. Nielson installs meters on TV sets, VCRs and cable boxes to automatically track when the TV sets are on and what channel is being watched. This data is sent to the Nielsen central computers via modem every day, and is made available to broadcasters and advertisers within 36 hours. Nielsen also uses "People Meters" that are attached to the TV set meter. Family members are assigned their own buttons, which are pushed when they are watching a show. This enables broadcasters to know the average age of the viewers of a particular program.
