Book publishing, like with any other creative product, is primarily about business, not art. Most normal publishers only want to publish books they think will sell, and will publish manuscripts that have possibilities of reaping good sales. Sensible publishers will try to publish good manuscripts under the logic that quality is appreciated. Vanity publishers really don't care either way and will publish anything, as they make their money off the authors rather than the audience. Some publishers go a step further. They churn out books as if they were a machine, and authors were merely cogs.
The result is Extruded Book Product. A type of book that is thoughtlessly put out once a month (or more often sometimes) by a publisher that usually hires multiple writers to anonymously author the books, often under a pen name. By now, everyone knows that The Hardy Boys and Nancy Drew are actually written by multiple authors that use the same pen name. But there were times when this business model was more common - when there were a number of "book mills", so to speak, that pumped out (not always) crappy books like Hanna-Barbera pumped out (not always) crappy cartoons.
Different companies have different ways of doing this. Some companies, such as Badger Books, would commission a cover artist and a blurb, and then hire a writer to hastily put together something that fit both. Other companies would have individual writers come up with stories that fit the characters, while some companies would create story outlines ahead of time and hire writers to write based on the outline. Whatever it took to churn out book after book.
- In the current[when?] comic book run of Ghostbusters, Egon "wrote" a book by using a computer program to "Calculate an almost random pattern of words that positively stimulate the human brain" as an experiment. It was apparently quite well received.
- In Young Adult, Mavis Gary ghostwrites for an extruded YA series called Waverly Prep, using it to relive her own high school Glory Days.
- In Nineteen Eighty-Four, books for the proles are literally created by machine.
- The main character of Robert A. Heinlein's The Cat Who Walks Through Walls produces these for a living, generally of the romance variety, and the narrative digresses for a bit on the subject of these. Notably, at one point he notes that he tried writing war stories instead, but his experience as a soldier got in the way because he tried to make them too realistic to be decent stories. He also admits to cribbing the plot for one of his books from Richard Wagner's Der Ring Des Nibelungen.
- Heinlein knew whereof this character spoke. Outside of his science fiction efforts, Heinlein himself was a writer of extruded book products for several houses, most notably a series of stories about an overweight teen girl with self esteem problems known by the nickname "Puddin'"—whom Heinlein later reworked into the eponymous protagonist of his young adult SF novel Podkayne of Mars.
- Roald Dahl's short story "The Great Automatic Grammatizator" focuses on a machine that can do this—but then they start buying out the real authors to corner the market...
- In the third book of Gulliver's Travels, one of the absurd projects undertaken by the members of the Grand Academy of Lagado was a device to mechanically combine words, enabling books to be written with no input but raw mechanical effort.
- The musical Trixie True, Teen Detective is a spoof of such writing syndicates.
- Done in one episode of The Simpsons, where Lisa finds out that all the young adult books (including her favorite "Angelica Button" series) are really just based on market research by the publishing companies and then written by teams of writers desperate for work. The "authors" who have their names on the book are just made up, backstory and all, and are represented by actors. After finding this out, Homer and Bart assemble a team to create their own hit young adult novel, using Lisa as the author to be credited.
- William Shakespeare is the Ur Example. Theatre was one of the favourite pastimes of the Elizabethan era, and the audience was always hungry for a premiere, so producing a serviceable play in a matter of weeks was a necessary skill for a successful playwright. Shakespeare scholars have speculated that many of his early plays were actually co-written; also, there is the infamous Shakespeare authorship question.
- Alexandre Dumas is the Trope Maker. He was one of the first writers to turn literature in a commercially successful venture, and employed legions of ghostwriters to keep up with the ever-growing demand for new books. Author of more than 1200 works, he (in)famously stated that he'd "had more co-authors than Napoleon had generals"; in a scandalous 1847 trial, it was proven that Dumas churned out novels at a faster rate that the fastest copyist in France on a 24h works schedule.
- As mentioned above, Badger Books used this model. They did have at least one author who tried to work within the constraints of this type of design to at least make his stories enjoyable even if in a stupid way, so they were at least tolerable. Sometimes the company would actually recycle cover artwork for more than one book.
- Harlequin romance novels are done this way, although without the "anonymous author" part. Authors publish under their own names or individual pseudonyms, and sometimes gain distinct followings which even cross series lines.
- Tom Swift was written this way. The first Tom Swift book, Tom Swift and His Motorcycle, was written by "Victor Appleton," also the "author" of the Don Sturdy series. Decades later, "Victor Appleton II" wrote the Tom Swift, Jr. series. Edward Stratemeyer, the editor/publisher, didn't just throw out ideas, he oversaw the whole process and came up with the concept for all the books. Other series, such as Nancy Drew, the Hardy Boys, and the Bobbsey Twins, all worked this way too, since they were all properties of the Stratemeyer Syndicate.
- Although, originally, Nancy Drew and The Hardy Boys weren't quite so bad as other Stratemeyer works. While Stratemeyer came up with the idea for each series and an outline for each book, each series was given to a specific ghostwriter (for the most part) to bring the series to life, Mildred Wirt Benson for the Nancy Drew books and Leslie McFarlane for The Hardy Boys, both of whom wanted to elevate their series above the Extruded Book Product label. Each wrote the majority of the first books (Benson wrote 23 of the first 25 Nancy Drew books, and McFarlane wrote 19 of the first Hardy Boys stories.)
- The Goosebumps series eventually turned into this; according to rumor, R.L. Stine eventually started working with ghostwriters to keep up with the demand for new stories.
- James Patterson and his army of co-writers, especially with his YA books. He seems to write Maximum Ride on his own, but both Daniel X and Witch & Wizard have ghost writers.
- Every Animorphs book between #24 and the finale was ghostwritten. They varied wildly in quality, and there were a lot of events and morphs and such that only came up once before being forgotten.
- Many of the hundreds of Babysitters Club books fall victim to this trope.
- The Doctor Who Expanded Universe novels are basically written like this, at least in that they vary wildly in quality, and by using multiple authors they kept a schedule which would be impossible for just one writer. However, on the whole, they actually tend to be good.
- Like the Doctor Who Expanded Universe, the Magic: The Gathering tie-in novels vary wildly in quality. Writers also sometimes disagree about the mythology and source material, leading to inconsistencies between stories. In addition, due to the variance in both authors and settings, some of the books are of a completely different genre. (For example, the Ravnica novels are supernatural Police Procedurals.)
- A rare (at least, so far) example of a non-fiction publisher, and one of the most Egregious examples is Alphascript Publishing, whose "books" consist entirely of reprinted pages from The Other Wiki, usually with large prices and crappy production values.
- Perry Rhodan could not have had thousands of issues over a period of more than 50 years without creating new books this way.