"You must keep sending work out; you must never let a manuscript do nothing but eat its head off in a drawer. You send that work out again and again, while you're working on another one. If you have talent, you will receive some measure of success - but only if you persist."
~Isaac Asimov (1920 - 1992)~
Authors recognize that rejection and waiting for rejection are necessary evils of the publishing game. It is all about numbers. Traditional publishers approach your literary masterpieces like an investment. Is this a marketable book? Will it sell? How involved will the author be in promotion? You may improve your odds of being published by sending your work to multiple publishers and agents. While your work may not be right for one, doesn't mean that it won't be for another.
Self-publishing is a process that eliminates the scrutiny and wait time. However, the author must be willing to invest at least as much time (and money) in marketing and promoting as it took to write the book. While I am exploring a variety of publishing methods, submitting my work, and experimenting with marketing techniques, it is important to keep writing. It certainly takes the focus away from worry and self-doubt while maintaining confidence and motivation. Staying focused and being persistent will pay off in the end.
Keep your pen to the paper! Remember, inspiration is everywhere...