Lackington & Co.'s handwritten account of expenses for printing and publishing Frankenstein in January 1818 indicates that of the 500 copies printed, 459 (41 were given gratis to the author [6 copies], reviewers [16], copyright libraries [11], and booksellers who bought more than 25 copies [8]) were sold at 10/6 (ten shillings and six pence) per three-volume set. After deducting printing expenses, Mary Shelley's share was one-third of the profits, which came to £41.13.10 (forty-one pounds, thirteen shillings, and ten pence). Forty-one pounds is not a large amount of money, but the distribution of money on the basis of the retail cost of the book compares quite favorably with modern-day contracts between authors and publishers.In 1823, the first dramatic adaptation of the novel appeared on the stage, Richard Brinsley Peake's Presumption. In the wake of the play's success, William Godwin supervised the publication of a new edition of the novel while Mary Shelley was in Italy. Long thought to be an unmodified page-by-page reprint of the first edition, the two-volume second edition of 1823 has been shown (by E. B. Murray) to contain a number of substantive variants (the changes are probably owing to Godwin), and was apparently the text from which the third edition was set.
Autograph evidence suggests that some time after 1823, Mary Shelley was thinking of not merely a reprint but a significantly revised edition of her novel. A copy of the 1823 edition which once belonged to her and contains her handwritten annotations still survives, located in the Pierpont Morgan Library; known as the Thomas Copy, its annotations are recorded within angle brackets in James Rieger's 1974 edition of Frankenstein. Although, since the changes were not adopted for a published text, they lack any actual textual authority, their conspicuous presence in what for many years was considered the standard edition of the novel has led many critics to quote them as if they were part of the text. Occasionally, in the present edition a reader will come upon such a textual citation in a critical article and will recognize it by the fact that there is no linkage between that citation and the novel's complete text.
Mary Shelley did soon have the opportunity to revise her work and remove the inadequacies she saw in its original form. As she describes the process in the Introduction to the third edition, she was approached by Henry Colburn and Richard Bentley, editors of the Standard Novels series, to produce a new edition of Frankenstein. The editors of this series of popular reprints encouraged their authors to introduce enough revisions that the novels might be newly copyrighted. Mary Shelley welcomed the opportunity, not merely making a great many verbal corrections, but entirely rewriting the first chapter. (The textual variants and a complete synoptic collation of the 1818 and 1831 editions are available in this edition.)
Mary Shelley could not have seen that the decision to publish her novel with Colburn and Bentley was unfortunate. By giving them the copyright to Frankenstein, she forestalled the novel's reappearance in England until the 1860s.