One reason we find it difficult to analyze advertising's effects introspectively and why advertising has remained a mystery for so long is that these effects are often so simple and so small that they fall short of outright persuasion. Advertising influences the order in which we evoke or notice the alternatives we consider. This does not feel like persuasion and it is not. It is nevertheless effective. Instead of persuasion and other major effects we should look for 'feathers', or minor effects. These can tip the balance when alternative brands are otherwise equal and, through repetition, can grow imperceptibly by small increments over time.