|•||Why do people buy bottled water that is available free from the tap?|
|•||Why does advertising work on everybody else but not on us?|
|•||Why do advertisers keep repeating an ad that we have already seen?|
All these questions reflect the general belief that advertising works by persuading us, yet we don't feel personally that we are at all persuaded by it.
Why is it so difficult for us to introspect on advertising and how it influences us? Because we look for major effects, that's why! Too often, we look for the ability of a single ad to persuade us rather than for more subtle, minor effects. Big and immediate effects of advertising do occur when the advertiser has something new to say. Then it is easy for us to introspect on its effect.
But most effects of advertising fall well short of persuasion. These minor effects are not obvious but they are more characteristic of the way advertising works. To understand advertising we have to understand and measure these effects. When our kids are growing up we don't notice their physical growth each day but from time to time we become aware that they have grown. Determining how much a child has grown in the last 24 hours is like evaluating the effect of being exposed to a single commercial. In both cases, the changes are too small for us to notice. But even small effects of advertising can influence which brand we choose, especially when all other factors are equal and when alternative brands are much the same.
It is easiest to understand this with low-involvement buying situations. The situation is like a 'beam balance' in which each brand weighs the same. With one brand on each side, the scale is balanced. However, it takes only