Sometimes, an idea doesn't quite fly. Maybe because the author had the bad luck to mis-time the market, or perhaps because she's struck at the story from the wrong angle. Or it could be, it's not ripe yet -- or it just plain stinks like Limburger cheese. (Happens to the best of us!)
In some cases, the author may recognize that something's off and not bother submitting. (You get better at recognizing this with experience.) A lot of other times, submissions will be sent out and rejected. Editors may compliment the author on the writing or the characters or some aspect of the plot, but in the end, the project isn't picked up, for one reason or another.
At some point, the author (or her agent) will come to the sad conclusion that this manuscript or proposal's had its shot. It's always a tough moment, and a little grieving's certainly in order.
But whatever you do, don't go burying the body. Do not toss, shred, or delete your work unless you've carefully saved a backup copy. Because often, sometimes years later, you're going to think about it, and you may suddenly realize exactly where you went wrong and how to fix it, or what elements are worth a second look.
I can think of one case where I had what I knew was a strong, complex idea, but I wasn't yet experienced enough to write it. My first attempt was lousy, as were the second and the third. They were so awful, I didn't bother to submit them and couldn't even place in the one contest I entered for feedback (and this was after I had published a half-dozen books, albeit in another subgenre). As I gained confidence and sharpened my skills, however, I came to a point where, with a couple of years' distance from the original story, I was able to make a fresh start, which sold quickly and went on to become my second romantic suspense novel, Fade the Heat.
Flash forward a year or two later, when I wrote a trilogy proposal. My then-agent loved it, and I was psyched about it. Though it went to committee at more than one publishing house, something was clearly off with the proposal, which died a slow and (at least to me) very painful death.
I wrote a different book to clear my head, then tried revising the proposal and giving it another shot. No dice, so I gave up on it... except that there was something in it I couldn't quite let go of. So I pulled the central story idea (my favorite) out of what was to have been the second book, and I sold it as a stand-alone. (This book, Triple Exposure, was released last August.) Later, I went on to strip out the setting (from its geography to its economic and political complexities) and certain characters from what I'd meant to be Books 1 and 3 and used those "spare parts" in creating what will be my next two books. As I'm working on the two of them, I keep going back to look up facts from that original, failed proposal, which somehow breathed life into three books after all. (Three very different books. And far better books than the original proposals, in my opinion.)
My most recent sale, for another upcoming book, came out of a little mini-proposal I've had stored on my hard drive for about three years (without submitting it), and I have yet another partial proposal that I've finally realized how to make work, after several years and multiple attempts.
The moral of the story is that a lot of failures aren't. They're simply "not-yets," so don't waste them. Store them, back them up well, and save them, because you never known when one will be worth reworking or provide exactly the spare part you need to make a new book run.
So what about you? Have you even used an old project as an "organ donor" for a new one? Or have you gone back to rework a not-yet manuscript because it wouldn't turn loose of your imagination?