Is she or isn't she a customer?
Very often we think in term of consumer marketing versus customer marketing; one focused on acquisition and the other focused on retention. We even allocate budgets as above and below the line further separating one idea from the other. However, in the age of showrooming, the distinction between being a consumer and a customer is more often down to a fleeting moment in time and a choice.
Will she buy?
Similar to Schrodinger's Cat of quantum physics that is both alive and dead until we open the box and look in an individual exists in both states until she actually buys. Since it is just one individual, we might want to consider 'customer' as only an attribute or descriptor rather than a separate and distinct class. Clearly campaigns can select an audience based on that knowledge, but in the world of 'omni-channel brand experiences' the messaging and marketing needs to be integrated. One of the worst things a brand can do is create cognitive dissonance thru conflicting programs - like offering discounts to new customers while not rewarding or recognizing loyal ones.
There are only consumers, some of them just happen to have a history of transactions that we can see in the rear view mirror.