Know-How Exchange : Advertising/PR

There are formula approaches to this and most advertising agencies with media departments can run these analyses very easily. You can also do some very simple guesstimating on your own.

Start with the average frequency (i.e., gross rating points divided by reach). Since you know that the minimum frequency among those you reach is 1, you can probably assume that your lowest viewing quintile sees the advertising 1.5 times (i.e., once or twice). The middle quintile sees the commercial at the average frequency. So you can assume the 4th quintile is roughly halfway between 1.5 and the average frequency.

On the high end, you can guesstimate how many times a viewer would see the advertising if they actually saw it, say, 75-80% of the times it appeared. That's pretty high, so maybe 65% would be more appropriate. (Apply some judgment based on the schedule itself.) Then the 2nd quintile would be whatever it takes for the weighted average of the 5 quintiles to equal the average.

It's not a perfect metric, but I'm not sure the agency formula is that much better. And it will begin to create some understanding of what the quintile analysis would show, how to use/interpret it, and whether it's worth a more precise calculation.

I've assumed you know your total gross rating points (GRPs), and that you have a good fix on average reach and frequency (which, multiplied should equal gross rating points). If not, you will need to back up to the estimate of those three factors: reach, frequency and GRPs. That's another issue altogether.