Tag Archives: reach

TV Media Planning Terms – calculating media reach and frequency using TVRs

Published / by Simon Foster

When media planners develop TV campaign plans they are often optimising the relationship between three sets of numbers:

  1. TVRs (or GRPs, or TRPs) – TVRs or TV rating points are a reflection a target audience using both demographics and geography. If there are 50m adults in the UK then 1 Adult National TVR is 1% of 50m – 500,000. If a national programme is watched by 2m adults it delivers 4 TVRs.
  2. Reach (or coverage) – Reach is the percentage of your target audience that is reached by a spot or a campaign.  TVRs build reach and frequency.  This is explained in more detail here.
  3. Average opportunities to see (OTS) – Average OTS is the number of times on average that a member of your target audience will see you ad.

There are some simple calculations to illustrate how these numbers work together.  There is one thing you will need to begin this process and that is a reach curve. A reach curve looks like this:

This curve describes the relationship between TVRs and reach. It  illustrates how your reach (sometimes called coverage) increases as you add more TVRs to your campaign.  You will see that with each additional 100 TVRs you add to your campaign, your reach increases more slowly. In practical terms this is because some of your target audience will see you ad more than once, even in the early stages of the campaign. This is called opportunities to see or OTS.

How do  we calculate OTS?

OTS is calculated by dividing your TVRs by your reach: At 300 TVRs we have about 70% reach. That means the average OTS is 300 / 70 = 4.2.

How many TVRs do you need?

To calculate this you need to multiply your target reach by your required OTS. So if you wanted 70% reach at 4 OTS your calculation would be 70 x 4 = 280 TVRs. If you wanted 70% reach at 5 OTS you’d need 350 TVRs. If you wanted 85% reach at 7 OTS you’d need almost 600 TVRs.

Can we calculate reach from TVRs and OTS?

Yes, but only to a point. Reach = TVRs /  OTS. So if you are planning 50 TVRs at 1.5 OTS it would seem that your reach would be 30%. However, reach is not easily predictable. This is for two reasons:

  1. First with you will see that whilst the growth in TVRs is linear, the growth in reach is non-linear i.e. it decreases as you add on every 100 TVRs. Between 0 and 100 TVRs we generate 50% reach. But when we add on the next 100 TVRs we only generate 65% reach at 200 TVRs.
  2. Different types of campaign on different stations, phased in different ways, with different use of daily schedules (dayparting) will increase reach in different ways. For example, a campaign that runs in weekday daytime between 9am and 5pm may struggle to get over 50% reach even at more than 300 TVRs. This is because you will not be reaching the audience that is working during the day.

How do TVRs build media reach and frequency?

Published / by Simon Foster

As we saw in the “what is a TVR” post a TVR is a percentage of a given target audience in a given geographic base.  But is a TVR any more than that? Well, yes it is. A TVR is an important factor in calculating how media activity builds reach and frequency. Reach is the percentage of your target audience seeing your ad at least once. Frequency is the number of times they see it.

How TVRs build campaign reach

Let’s assume you buy 100 TVRs in a given region. We know from our last post on TVRs that 100 TVRs is an amount of audience that is the equivalent of 100% of our target audience base.  But here’s the first important lesson in how TVRs build reach and frequency. 100 TVRs will not deliver 100% reach of that base.  In fact 100 TVRs will probably build around 50-60% reach depending on how those TVRs are distributed in the plan. So what is delivered by the TVRs that don’t deliver reach? Well, they deliver frequency.

How TVRs build campaign frequency

In the early stages of campaign, most people will see the ad only once. But some will see it twice and some may see it three times. Let’s say, for example, that 50% see it once, 20% see it twice and 15% see it three times 10% four times and 5% five times. These percentage total 100 and this is effectively how your 100 TVRs are distributed. This is called frequency distribution.

How to estimate frequency from TVRs and reach

There is a simple formula for estimating how TVRs deliver both reach and frequency.  Let’s continue to assume you have 100 TVRs. Frequency (sometimes called average opportunity to see or OTS) is calculated by dividing your campaign reach into your campaign TVRs. So, if you have 100 TVRs and your campaign delivers 50% reach then your average OTS is 100/50 = 2.

How many TVRs does my campaign need to be effective?

This depends upon whether or not you adopt the view that reach is more important than frequency.  Modern “recency” planning advocates (John Philip Jones, Erwin Ephron, Byron Sharp) argue that each point of reach will deliver more sales response than additional points of frequency (i.e. the percentage of people seeing the ad twice, three times etc). So they advocate building maximum reach on a weekly or a monthly level, but not building frequency. To achieve this objective media planners will seek between 100 and 150 TVRs per week and often plan the delivery of these TVRs in a week on, week off “drip” pattern. This type of campaign plan tends to suit campaigns that are designed to regularly remind consumers about a product they are already aware of.

More traditional media planning approaches (Krugman for example) suggest a minimum frequency of 5 OTS before a message begins to resonate with a prospect.  Our calculation tells us that if we want to achieve 80% reach at 5 OTS we will need 80×5 = 400 TVRs. Targeting an average of 7 OTS would require 560 TVRs. You can see why a launch campaign would typcially be around 600 TVRs.

More advanced forms of planning use statistical modelling to estimate the sales response curve to advertising. These models show how budget and TVRs drive sales response (could be retail or online sales) on a weekly basis and forecast when spend levels will hit diminishing returns. For more on this please see www.mus3.co.uk

Thanks to Ivan Clark for comments.