When Alloy Entertainment fired L.J. Smith from the popular young-adult book series "The Vampire Diaries" and replaced her with a ghostwriter three years ago, a civil war broke out among fans. One camp swore fealty to the characters and embraced the new books, which still feature Ms. Smith's name prominently on the cover as the series' creator. The other, more vocal faction sided with Ms. Smith and boycotted the ghostwritten novels.

"I would not read those books if they were the last books on earth," said...