TV Commercial Viewership Ratings [Basics]: Explaining the Fundamental Knowledge You Need to Know
Viewership rating is one of the important metrics in TV commercial effectiveness measurement and planning. In an increasingly diverse viewing environment, professional knowledge to deeply understand, analyze, and utilize viewership rating data is required to plan and execute cost-effective commercial strategies. This article explains the basic knowledge, such as the definition of viewership ratings, measurement methods, and major metrics, in an easy-to-understand manner. Specific examples of utilizing viewership rating data, as well as effective planning and effectiveness analysis, will be detailed in the sequel, 'TV Commercial Viewership Ratings [Applications],' so please take a look at that as well!
1. What are TV viewership ratings?
In the first place, viewership rating is one of the metrics that measures how many people watched a TV program or TV commercial during the time it was broadcast and indicates the percentage of viewers during a specific time slot. There are many companies that measure viewership ratings, but TV stations and the advertising industry utilize viewership rating data from a research company called Video Research (VR). Viewership rating data is surveyed for each broadcast area, and by measuring viewership ratings, you can confirm how much that program or commercial was watched.
However, since it is calculated statistically from the survey results of a sample of households, there is a possibility that a certain degree of error may occur in the viewership rating figures.
2. Measurement methods for viewership ratings
People Meter System (PM System)
There are several types of viewership rating measurement methods, but the one currently used as the mainstream is the People Meter System (PM System), which is a method of collecting viewing data through a dedicated measuring device (People Meter) installed in households cooperating with the survey. In this system, when viewers watch TV, they press a personal remote control button linked to their attribute information (gender, age, etc.). Through this, detailed data on 'who watched which channel and when' is recorded and aggregated in real time.
The greatest feature of the PM system is that it can measure not only 'household viewership ratings,' which indicate whether the entire household was watching, but also 'individual viewership ratings,' which can grasp the viewing status of each individual. This makes it possible to analyze in detail how much a specific target audience (e.g., women in their 20s, men in their 50s, etc.) watched a program or commercial, and it is being utilized for more precise advertising strategies and program scheduling.
Reference: It's so different between the past and the present! The history of viewership rating measurement
Before the PM system, which is currently the mainstream for viewership rating measurement, became widespread, the following methods were mainly used to grasp TV viewing status. These traditional methods were utilized within the technical constraints of the time, but each had its own challenges compared to current systems.
Mechanical Household Viewership Rating Survey System
Overview: A method of installing a dedicated machine in specific target households and measuring viewing data through an internet line or telephone line. Unlike the manually recorded People Meter, TV viewing status is aggregated fully automatically and in real time.
Features and Challenges: While fully automatic and real-time measurement is possible, it could only measure household viewership ratings and could not grasp individual viewing status.
Diary-style Questionnaire Survey
Overview: A dedicated survey form (diary) is distributed to households cooperating with the survey, and the person who watched TV records by hand 'when, who, which program, and for how many minutes they watched.' This method is conducted at an arbitrary time and period decided by Video Research and the broadcasting stations in each district, but data is usually aggregated after a request to fill it out on a weekly basis.
Features and Challenges: At the time, it was characterized by the ability to record programs watched by individuals. However, it had the challenge of being prone to human error and bias, such as forgetting to fill it out, misremembering, or 'self-reporting' that they were watching a popular program. Also, there was no real-time immediacy.
The PM system was developed to overcome the challenges that these traditional measurement methods had, such as 'human error,' 'lack of real-time capability,' and 'unclear who is watching'. By automatically linking TV viewing status with individual attributes and collecting and aggregating them in real time, the PM system provides more accurate and detailed viewership rating data and has become an indispensable information source in modern commercial strategies and program scheduling.
3. Types of major viewership rating metrics
In recent years, TV viewing is conducted in various forms, not only real-time viewing but also 'time-shift viewing,' where it is recorded and watched later. To respond to such changes in the viewing environment and to grasp the more accurate actual viewing situation, there are various metrics for viewership ratings.
Real-time viewership rating
The "household viewership rating" and "individual viewership rating" often heard in news and other media refer to this "real-time viewership rating." It is an indicator that shows the percentage of households or individuals watching in real-time during terrestrial broadcasts, BS broadcasts, and some specialty channel broadcasts.
Time-shift viewership rating
The time-shift viewership rating is an indicator that shows the percentage of viewers who watched a program via recording or on-demand within 7 days (168 hours) after the broadcast ended. With the recent spread of recording devices and the diversification of lifestyles, the proportion accounted for by this time-shift viewing is on an upward trend.
Gross time-shift viewership rating
In relation to time-shift viewing, there is also an indicator called the "gross time-shift viewership rating." This is an indicator calculated by counting the number of times the same individual watched the same program multiple times during time-shift viewing within 7 days after the broadcast. For example, actions such as repeatedly watching specific scenes of a favorite drama or movie, or watching multiple times to deeply understand the content, are counted as one time in the time-shift viewership rating, but are added up by the number of times in the gross time-shift viewership rating. This indicator is useful for measuring the level of viewer engagement with the program and the repeatability of the content.
Total viewership rating
"Either watched in real-time or watched via time-shift", or an indicator showing the percentage of those who watched via both. If watched both in real-time and via time-shift, it is aggregated as "1 count (not counted as multiple viewings)." In other words,
"Total viewership rating = <Real-time viewership rating> + <Time-shift viewership rating> - <Duplicate viewership rating>", making it an indicator that shows the spread of viewership on a program basis. By understanding these indicators, it becomes possible to grasp not just momentary viewership ratings, but also how and how many people are being reached by programs and commercials from multiple perspectives.
4. What are household viewership ratings and individual viewership ratings?
While "viewership ratings" are widely known as indicators for measuring the effectiveness of TV programs and TV commercials, there are broadly two types: "household viewership ratings" and "individual viewership ratings." By understanding the differences between these indicators, you can more accurately grasp program viewing trends and viewer behavior.
Household viewership rating (GRP)
The household viewership rating (GRP) is the percentage representing how many households were watching TV during a specific time slot among households owning a TV that are subject to the survey. GRP stands for Gross Rating Point, which means the gross viewership rating over a certain period during which TV commercials were aired. Since household viewership ratings count the number of households, the detailed number of viewers cannot be grasped.
Example: If 5 out of 100 households surveyed were watching the program, the household viewership rating is 5%.
Individual viewership rating (PRP)
The individual viewership rating (PRP) is the percentage showing what percentage of people were watching TV among all family members aged 4 and older in the surveyed households. PRP stands for Persons Gross Rating Point, which means the gross viewership rating of individuals. In contrast to GRP, which calculates the gross viewership rating on a household basis, this is the percentage showing how much individuals were watching TV during a specific time slot, so it is used when grasping viewership ratings by gender and age.
Example: If 5 out of 100 individuals surveyed were watching the program, the individual viewership rating is 5%.
Reference: Details of individual viewership rating segments
A major feature of individual viewership ratings is that viewers can be captured in diverse "segments." Representative segments are the following 8 segments by gender and age, which makes it possible to analyze the actual viewing status of target groups in more detail and perform highly accurate commercial planning.
At Telecy, in addition to the gender and age segments held by broadcasters, it is possible to perform planning after targeting annual income, regional characteristics, occupation, and age segments in 1-year increments. By combining these segments, you can grasp the viewing behavior of more niche and specific target groups. Note that viewership ratings that do not narrow down by specific segments and target all individuals aged 4 and older surveyed are called "individuals overall." Even when simply written as "individual viewership rating," it generally refers to this "individuals overall."
5. What does "1% viewership rating" mean?
Number of viewers per "1% viewership rating"
TV program viewership ratings are often a topic of conversation, but do you know how many viewers 1% of a rating actually represents?
The number of people represented by a 1% viewership rating varies depending on the survey area, but in the Kanto region*1, 1% means that 399,000 people are watching the program. (For individuals overall)
Since the population differs by area and characteristics, the number of people per 1% naturally changes as well. Please note that this does not apply to areas other than the Kanto region.
*1: The estimated population owning private TVs in the Kanto region is 39,932,000. Source: Cited from Video Research Ltd., "FY2024 Estimated Number of Households and Population within Survey Areas"
Estimated values for household viewership ratings and individual viewership ratings
We often say that viewership ratings are "high" or "low," but even a 1% rating reaches a significant number when converted to actual households or actual numbers of people.
In the case of a 1% household viewership rating: Estimated that approximately 180,000 households in the Kanto region are watching
In the case of a 1% individual overall viewership rating: Estimated that approximately 399,000 people in the Kanto region watched
In this article, we have introduced the basic knowledge of TV commercial viewership ratings. In the related article, "TV Commercial Viewership Ratings: [Advanced Applications]," we explain concrete examples of utilizing viewership rating data, effective planning, and effectiveness analysis, so please take a look at that as well.
At Telecy, we provide integrated marketing communication services based on the goals and challenges of client companies, and we provide consistent support from strategy formulation to maximize cost-effectiveness to CM production, media planning, and effectiveness analysis.
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