The great power latent in this form of suggestiveness is well known to knaves in America where it is most employed.

This is the whole secret of the value of advertising.
People yield to the mere repetition in time.

Attention and Interest may in this way be self-induced from repetition.
It is true that an image or idea may be often repeated to minds which do not think or reflect, without awakening attention; _per contra_, the least degree of thought in a vast majority of cases forms a nucleus, or beginning, which may easily be increased to an indefinite extent.

A very little exercise of the Will suffices in most cases to fix the attention on a subject, and how this can be done will be shown in another chapter.

But in many cases Attention is attracted with little or no voluntary effort.