Mark Twain,
Mark Twain's Letters — Volume 3…
“ I have been thinking, yesterday and to-day (plenty of chance to think, as I am abed with lumbago at our little summering farm among the solitudes of the Mountaintops,) and I have concluded that I can answer one of your questions with full confidence—thus: Make it a subscription book. Mighty few books that come strictly under the head of literature will sell by subscription; but if Uncle Remus won't, the gift of prophecy has departed out of me. When a book will sell by subscription, it will sell two or three times as many copies as it would in the trade ”
