Even after eighty years of publication, Simon & Schuster is still putting out several Hardy Boys and Nancy Drew titles each year, thanks to ghostwriters and an assembly-line-like process:
Book packagers are a kind of outsourced labor, not unlike factories in China or tech-support centers in Mumbai. They develop new story ideas, recruit and manage freelance writers, and edit the first drafts of series books.
Writers give up bylines, royalties, and all the glory, but they remain anonymous—a bonus for introverted authors—and they receive a steady paycheck as long as they keep the mysteries coming.