One question editors are frequently asked at cocktail parties is, "where do you find the books you publish? Do they all come from agents?" Some editors, probably wiser ones than I, simply answer, "Yep." My answer is, you never know where you are going to find a publishable book or a promising author. True, the vast majority of titles I publish (probably 95 percent) come from literary agents. But a few come from other sources. When I was at Oxford University Press, many of our authors submitted their work directly, and an important part of an academic editor's job is maintaining relationships with important people in the field (whose graduate students may be the star authors of the future). I still, happily, publish some scholars whom I deal with directly.
I also believe that a good editor will create his own books: instead of sitting at a desk waiting for someone to send you something, you think of an idea for a book and go looking for the right author. Very often, that author has an agent, but creating a book this way is different from, and sometimes more satisfying than, leaving it to other people to bring you stuff. I have published several titles, from how-to books to award-winning works of history, that came from me pitching ideas to authors.
Another happy occurrence is when authors refer their friends or colleagues to you. Some of my best authors have come to me through authors I've worked with who suggested a friend or colleague contact me. Again, often this connection involves an agent, but it's not quite the same as the agent flipping through her Rolodex and putting my name on a list. I always take referrals from an author very seriously whether or not an agent makes the submission.
But as I say, you might find an author anywhere. Many years ago, before internet shopping existed, I was an impecunious editorial assistant who bought shoes from mail-order catalogues. One day I phoned an order in to Land's End and found myself having a longer conversation than usual with the customer service rep. Hearing that my shipping address was "Persea Books," he said, "Oh, are you a publisher? I'm just learning about the publishing business now, because I'm writing a novel." This aspiring writer was working at Land's End to pay the bills, and while he actually had an agent, he wasn't going to miss an opportunity. My shoes arrived promptly, with a literary fiction manuscript as a free bonus.
This story might be funnier if the manuscript were lousy, but on the contrary, it was quite well written. In fact, I thought it was too quiet and literary to sell, and turned it down--but a couple of years later, I saw the same manuscript was published by Simon & Schuster. Where do you find authors--or publishers? You never know.
P.S. This story is not meant to suggest I yearn for unsolicited and unagented manuscripts. I will write at another time about the slush pile, and why I don't read it any more.