One of the tenets of Release Your Writing: Book Publishing Your Way is the need for writers to self-advocate.
No one believes in your work more than you do, and its unlikely the glint of your perfect prose will be shine in an agent's or editor's eye.
We hear that mainstream publishing is harder to achieve than ever. It rejection is a frustration for you, take heart in this recent news story:
I frustrated writer, David Lassman disguised Jane Austen's Pride & Prejudice and sent it off to 18 publishers. One well-read editor spotted the fraud, but the other 17 publishers all rejected or ignored it. Lassman submitted the manuscript under a female pseudonym, and changed only the title and character names. Odds are he's now a big fan of self-publishing.