All the books tell of the craze in sending and collecting postcards which gives us our secondary part in the hobby today.  More cards then, more cards now.  This letter from 1906 makes evident the importance of the medium not only as popular entertainment, but as early 20th century business advertisement.  Here Mr. Gould encourages a druggist or stationer in New Hampshire to buy views which the company has already published and perhaps to photograph less well-known local scenes.  When sold this way, the cards often bore the imprint of such a merchant, with or without the Rotograph logo--see the example on the "Backs" page.  Should we consider these early Rack Cards?