Pen names. Many more authors use Pen names than you would think.
My mother recently went a little crazy over the fact that I've chosen to use a pen name for my first novel, A LIFE BEYOND YESTERDAY. I chose a pseudonym for one simple reason: The story is written for an entirely different genre than I intend to do most of my future work.
Why can't I use the same name in Women's Fiction and Urban Fantasy? Marketing. It just doesn't work. However, there are countless other reasons for using a pseudonyms.
Stephen King wrote as Richard Bachman to avoid criticism over publishing too many books in the same year.
Emily Bronte wrote as Ellis Bell because, in her time, being an author was a man's game.
Joanne Rowling became JK Rowling to entice more young male readers to her Harry Potter series. And, after publishing an exorbitant amount of books as Nora Roberts, Nora now also writes as JD Robb. Nora has also been published under the names Jill March and Sarah Hardesty.
Does it bother me that my first book won't be published as written by SJ Drum but rather as written by my pseudonym, Clara LaVeaux? Not. One. Bit. All that matters to me is that it's a good book that people want to read ... and hopefully recommend to their friends.