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.