How many times do people need to see my message before they buy?
Marketers obviously need to take a view on how much they need to advertise in order to have an effect in the marketplace. They need to know how much is enough – and how much is too much (seeing an ad too many times may produce negative effects).
Only then can they estimate how much they will need to spend to have the desired effect.
In a simple world, an advertiser might determine from various sources that he needs to reach his target...