Many propositions can be exploited in this way. In other instances a
much more complete statement must be made to elicit a reply. Here
the illustrated personal letter comes into use. And it is
significant that in a number of specific cases these letters in post
card form have been far more productive of inquiries than ordinary
letters on the same proposition. Their unique form, the accompanying
illustrations, by their very contrast in method of approach, prompt
a reading that the letter does not get.
