A "first edition" per se is not a valuable collectible book. A popular work may be published and reprinted over time by many publishers, and in a variety of formats. There will be a first edition of each, which the publisher may cite on the copyright page, such as: "First mass market paperback edition". The first edition of a facsimile reprint is the reprint publisher's first edition, but not the first edition of the work itself.
Publishers often use the same typesetting for the hardcover and trade paperback versions of a book. These books have different covers, the title page and copyright page may differ, and the page margin sizes may differ (same type area, smaller trim), but to a bibliographer they are the same edition.
From time to time, readers may observe an error in the text (or, in the days of metal type, a piece of broken type), and report these to the publisher. The publisher typically keeps these reprint corrections in a file pending demand for a new print run of the edition, and before the new run is printed, they will be entered.
The method of entry, obviously, depends on the method of typesetting. For letterpress metal, it typically meant resetting a few characters or a line or two. For Linotype, it meant casting a new line for any line with a change in it. With film, it involved cutting out a bit of the film and inserting a new bit. In an electronic file, it means entering the changes digitally.
Such minor changes do not constitute a new edition, but introduce typographical variations within an edition, which are of interest to collectors.
First edition most often refers to the first commercial publication of a work between its own covers, even if it was first printed in a periodical: the complete text of Ernest Hemingway’s The Old Man and the Sea appeared in the September 1 1952 issue of Life magazine, yet the generally accepted “first” edition is the hardcover book Scribner’s published on September 8 1952.
The term "first trade edition," refers to the earliest edition of a book offered for sale to the general public in book stores. For example, Upton Sinclair's 1906 novel The Jungle was published in two variant forms. A "Sustainers' Edition", published by the Jungle Publishing Company, was sent to subscribers who had advanced funds to Sinclair. The first trade edition was published by Doubleday, Page to be sold in bookstores.
A small minority of book collectors, particularly in the science fiction field, hold that the earliest bound copies of a book--promotional advance copies: bound galleys, uncorrected proofs, advance reading copies sent by publishers to book reviewers and booksellers--are the true first edition.
Non-fiction, academic and textbook publishers generally distinguish between revisions of the text, usually citing the dates of the first and latest editions on the copyright page. However, even this rule of thumb is sometimes bent. A new textbook with a different format, title, and authors may be called a "second edition" because a previous textbook is being counted as the first, despite being essentially a different book (sharing only the subject with the new one). This stretch of the definition is done for its marketing effect, because the new textbook may seem more authoritative to the potential buyer if it implies that there have been "previous editions".
Conversely, they may decide to call a version that is really not very different a "new edition" (n+1th).
The qualitative difference, then, between a "revised edition" and a "new edition" is subjective. This is analogous to the way that software publishers may call one update "version 3.7" but call the next update "version 4" instead of "version 3.8". The difference is their subjective sense of whether the differences constitute something very different or merely slightly different. Sometimes the distinction has more to do with marketing than with reality (that is, encouraging buyers to think that something slightly different is very different).
The logic of co-editions has often been to use the existing distribution systems of the different publishers in each country rather than establishing new distribution systems.
Advancing IT and the globalization of publishing have been blurring the lines of what co-edition means. For example, anything published online is effectively published worldwide. Also, large multinational publishers now have existing distribution systems for their hardcopy books in many countries, so they don't need to partner with other companies. They may issue a book under a different imprint for each country, but the imprints are parts of the same parent corporation. The actual manufacturing of the books may be done in China regardless of where the copies will be sold.
A publisher hopes to recoup a large amount of the book's initial costs from the sale of the book's first print run. A variety of commercial and logistic factors are thus considered in deciding the number of books in a print run, and their unit price.
Demand for additional print runs after the first is always hoped for, because they increase the book's overall profitability. Once the fixed costs of developing, editing, typesetting, etc., have been covered by the first sales revenue, any additional sales revenue tends to add to the profit margin (minus, of course, the costs of the additional materials, printing, binding, and distribution).
Sometimes a print run will be unsatisfactory for some reason, particularly with art and photography books where reproduction quality is paramount. It is usually destroyed by being pulped, but occasionally a defective print run may be shipped to a distant overseas market and sold there cheaply, depending on shipping costs.
If sales of the book do not meet expectations, the remaining stock of a print run will be remaindered.
Seconds are imperfect or damaged copies which are set aside from a print run. These will usually have their jacket clipped or marked in some way.
When a print run is sold out, the title is either reprinted or becomes out of print. With the advent of print on demand and e-book technologies, publishers can keep titles perpetually in print, and there are now few good reasons why any new book should ever become unavailable. As for old books, many are currently still out-of-print, but an era in which any book from any time can be downloaded or printed on demand, either for free or for the right price, is conceivable. Properly handling copyrights and sales will present a larger hindrance to arriving at this era than will technical limitations.
It thus protects the publisher's investment in typesetting, as well as the processes of design and selection that are reflected in the appearance of the text. It also covers modern editions of public domain works (such as the complete works of Shakespeare), and prohibits the reproduction of the layout (but not the work itself).