A third of the book is devoted to what you do once you've written your erotic novel. That's great if you already have the novel written and you're ready to get it ready to sell. If you're looking for how to write that dirty story, or that romance scene, you're out of luck.
Another third of the book is getting ready to write. You get the history of erotic novels in the United States, how to find the erotica you like, and reading it aloud to get a sense of it's style and power. It also details how do you deal with your family and friends reading something you're written that's sexually explicit, and what you can do about it. This stuff is helpful, but between it and the publishing guide you're really left with very little about how to write itself.
Once into the actual writing bit, Bright's exercises are helpful, but limited. She sets up the exercises and outlines the goals they should accomplish, and where to get ideas, but aside from saying that stringing together a bunch of sex scenes does not automatically make a plot and a good piece of erotica, she's pretty vague. She doesn't touch too much on characterization, and her chapter on mixing sex with other genres is disappointing as best.
The book focuses solely on erotica, and not even really writing it, but getting ready to do it, and then what to do once it's written. Her publishing section can be considered useful, she doesn't sugarcoat anything, including the amount of work writers have to do, and how no one gets rich overnight in the erotica business. However, it doesn't tie into how to write a dirty story, which is the title, and should be the bulk of the book.