Shepherd urged his listeners to enter bookstores and ask for a book that did not exist. He fabricated the author (Frederick R. Ewing) of this imaginary novel, concocted a title (I, Libertine), and outlined a basic plot for his listeners to use on skeptical or confused bookstore clerks. Shepherd eventually proved his point that the process of choosing bestsellers was flawed.
The success of the hoax (at least with bookstore clerks) may have been due in part to the popularity of James Boswell's London Journal, which was written in 1762-1763 but first published in 1950. The suggested plot of I, Libertine is remarkably similar to Boswell's account of his real-life adventures; booksellers may have believed I, Libertine was a fictional attempt to cash in on the interest in Georgian England Boswell's million-selling journal had created.
Bookstores became interested in carrying Ewing's novel, which reportedly had been banned in Boston. When publisher Ian Ballantine, novelist Theodore Sturgeon and Shepherd met for lunch, Ballantine hired Sturgeon to write a novel based on Shepherd's outline. Betty Ballantine completed the final chapter after an exhausted Sturgeon fell asleep on the Ballantines' couch, having attempted to meet the deadline in one marathon typing session. On September 13, 1956, Ballantine Books published I, Libertine simultaneously in hardcover and paperback editions with Shepherd seen as Ewing in the back cover photograph. In effect, the hoax actually begot the book. The proceeds were donated to charity.
A few weeks before publication, The Wall Street Journal officially exposed the hoax, already an open secret.
The front cover displays a quote: "'Gadzooks,' quoth I, 'but here's a saucy bawd!'". The cover painting by Frank Kelly Freas includes hidden images and inside jokes: The sign on the tavern, Fish & Staff, has a shepherd's staff and an image of a sturgeon, referencing both Sturgeon and Shepherd. A portion of the word often spoken on the air by Shepherd – "Excelsior!" – can be seen on the paperback cover in a triangular area at extreme left,where it is part of the decoration on the coach door. The hardcover dust jacket, with more of the illustration to the left, shows the entire word. Freas' artwork was typically more well known in the science fiction community (one of his magazine covers was adapted for a famous album cover by rock band Queen) and as one of the artists who was responsible for the iconic Mad Magazine mascot Alfred E. Neuman.