Unpublished authors often cite the case of John Kennedy Toole, who, unable to find a publisher for his novel, A Confederacy of Dunces, took his own life. Thereafter, his mother relentlessly championed the book, which was eventually published to great acclaim and earned him a posthumous Pulitzer Prize for fiction.
Yes, we say, that is a strategy, but it is a strategy that demands a remarkable level of commitment from the author's mother, and an even greater commitment from the author. And, of course, it puts a serious crimp on the book tour. But even more to the point, it will work only if you have in fact written a masterpiece that awaits only the further enlightenment of the publishing industry and the reading public to receive the treatment it deserves.