This story is a Succubus Diaries short. It can be read at any point in the series, and you do not need to read it to follow along with the printed books.
How did Jackie Brighton get turned into a succubus? She can't remember - all she knows is that she woke up in a Dumpster. This short story tells the tale of that night, and sheds a little light on her masters' motivations...
This story is available for free on the Pocket Website.
And B&N for free.
FOREPLAY is also available in the Succu-Bundle on Amazon.