Over/under delivery analysis. Many people use a circus tent pole as an analogy for media delivery. The core audience of a vehicle (be it a medium, a vehicle or a program) will tend to be the peak, but everything will contain other audiences that are not the primary and often will have every single group, as in the case of really broad-based media. It is important to understand the individual audience delivery to buy efficiently.
A second and equally important factor is that dispersion of the medium being considered will guide the creative unit that we plan to run. Highly dispersed media should run broad-based creative. Narrowly focused media, while less efficient overall, will be highly effective against their core audience and deserve narrower-focused creative.
Typically, we might see something like this:
One sees peaks and valleys, but, essentially, every target is present in almost every program. In reviewing a persuasion strategy, this has to be considered.
Bottom line: No medium delivers only on its core target, and this must be considered in the overall strategy.
Channel mixers. While many companies (such as Nielsen and Comscore) are finally coming out with channel mixers, there are two readily accessible mixers you can apply right now: the Sainsbury formula and the extended Sainsbury formula.
Sainsbury, also known as random duplication, uses a very simple formula to figure out the aggregate reach of a series of vehicles.
The basic formula is: Cn = 1 ((1-a) * (1-b) *
Cn = reach of N number of vehicles
a, b, c n = vehicles
The reach is the perimeter of the combination of vehicles.
Combined with GRPs and costs, the Sainsbury formula is a quick and effective way to look at media combinations for any plan.