Half the money I spend on advertising is wasted; the trouble is, I don't know which half.
Never stop testing, and your advertising will never stop improving.
Advertisements may be evaluated scientifically; they cannot be created scientifically.
The Google model of targeted advertising is appealing because it claims to cut down on waste. We need to ask how that efficiency can be brought to creative process.
What this means is that the first week of every new series of ads will continue to yield softer results than you can expect to see in weeks two and three.
Most national advertising is done without justification. It is merely presumed to pay. A little test might show a way to multiply returns