Serial killers are good business for authors. In a survey of 3,322 books about serial killer or true crime/murder, the most written-about serial killers emerge. The more books which mention or focus on a particular serial killer, the more popular that killer is.
The serial murderers represent people from around the world, dating from the 1800s to today. Many books are written about one specific killer, such as Jack the Ripper. Other books more encyclopedic, and cover multiple killers. These books often have a short chapter on dozens of different killers. Examples include She Devils: True Stories Of The World’s Most Notorious Female Serial Killers by Anne McDuff, and Hunting Humans: The Encyclopedia Of Serial Killers Vol. 1 & 2 by Michael Newton.
The top ten most popular serial killers, based on appearances in books, are Jack the Ripper (325), Ted Bundy (220),
Jeffrey Dahmer (168), Ian Brady and Myra Hindley (114), John Wayne Gacy (113), David Berkowitz/Son of Sam (99), Henry Lee Lucas and Otis Toole (99), Aileen Wuornos (96), Kenneth Bianchi and Albert Buono Jr./Hillside Strangler/s (87), and Henry DeSalvo/The Boston Strangler (87).
Some authors an companies produce useless or very low quality books about serial killers. They are nothing more than Wikipedia entries and stolen blog posts. Other times, an author will rewrite a book, under different titles (rather than release revised editions of the book). Other books are nothing more than high-school or university papers in printed format. I have tried to weed those types of books out.
As always, please feel free to share the chart, without alteration.