Quintile analysis. This is one of the oldest analytical tools we have, yet one of the most impressive. Every medium – and every vehicle in each category – has heavy users, average users and light users. In almost every situation, consumption is not a bell curve but, rather, a lopsided mountain where the heaviest users are responsible for most of the consumption. Typically, we would see this:
The 20 percent of the audience that watches the most accumulates 45 percent of the gross rating points (GRPs) in television. This pattern, which is repeated almost everywhere, means that at some point, any single medium bought becomes inefficient, as it will accumulate disproportionately more weight and money on heavy users and less on light users. For example, increasing the weight of a TV schedule might look something like this:
Let’s say we buy 500 GRPs. This might have a reach of around 65 percent in our primary target. Each quintile then represents 13 percent reach. Considering how GRPs are distributed and the simple GRPs/Reach = Average Frequency, we can see that the heaviest viewers will see the spot an average of 17 times while the lightest ones will see it fewer than two. Clearly, this is not ideal.
If we were to buy 50 percent more GRPs, thereby increasing the budget at least 50 percent, we would increase the average frequency by 35 percent (reach does not increase linearly). So now the heaviest viewers get to see the spot 23 times while the lightest ones see it fewer than three. Clearly, this is not ideal either but is way more expensive.
Bottom line: One single medium is not enough, and we need a media mix to buy efficiently.