adjusted to the particular size.  No less important than the size is the originality and the unusual form, the vivid color, the skillful use of empty spaces, the associative elements, the appeal to humor or to curiosity, to sympathy or to antipathy.  Every emotion can help to impress the content of the advertisement on the involuntary memory.  Unusual announcements concerning the prices or similar factors move in the same direction.

Together with the question of the apprehension and the vividness of the impression, we must acknowledge the frequency of repetition as an equally important factor.  We know from daily life how an indifferent advertisement can force itself on our mind, if it appears daily in the same place in the newspaper or is visible on every street corner.  But the psychologically decisive factor here is not the fact of the mere repetition of the impression, but rather the stimulation of the attention which results from the repetition.  If we remained simply passive and received the impression the second and third and fourth time with the same indifference with which we noticed it the first time, the mere summation would not be sufficient for a strong effect.  But the second impression makes the consciousness of recognition, thus exciting the attention, and through it we now turn actively to the repeated impression which forces itself on our memory with increased vividness on account of this active personal reaction.

We may consider how such factors can be tested by the psychotechnical experiment.  Scott, for instance, studied the direct influence of the relative size of the advertisements.[50] He constructed a book of a hundred pages from advertisements which had been cut from various magazines and which referred to many different articles.  Fifty persons who did not know anything about the purpose of the experiment had to glance over the pages of the book as they would look though the advertising parts of a monthly.  The time which they used for it was about ten minutes.  As soon as they had gone through the hundred pages, they were asked to write down what they remembered.  The result from this method was that the 50 persons mentioned on an average every full-page advertisement 6-1/2 times, every half-page less than 3 times, every fourth-page a little more than 1 time, and the still smaller advertisements only about 1/7 time.  This series of experiments suggested accordingly that the memory value of a fourth-page advertisement is much smaller than one fourth of the memory-value of a full-page advertisement, and that of an eighth-page again much smaller than one half of the psychical value of a fourth-page.  The customer who pays for one eighth of a page receives not the eighth part, but hardly the twentieth part of the psychical influence which is produced by a full page.