Publishers, from what I can tell, have the same problem. One thing that I'm struck by is how many novels that we now consider classic, or novelists who we now consider important, barely scraped into publication. Tolkien famously saw Lord of the Rings in print because of Rayner Unwin, the then nine-year-old (I think) son of a publisher liked LOTR. John Barth and William Goldman have both written about how close they were to pursuing other opportunities—a PhD and insurance, IIRC. A Confederacy of Dunces was only published after O'Toole killed himself. Melville's poetry was self-published IIRC. Virginia Woolf needed to start her own press.
There are probably others with similar stories.
Not only that, but I have to wonder who barely didn't make the cut. Given the large number of writers who skated into print, there must be at least an equally large group who "should" have, but left no marks on history sufficiently legible to trace.
I think about these issues a lot for two reasons. The first is that I've had many close calls with literary agents, all of whom eventually said, "I like you, but not in that way." The second is the technological environment: now that ebooks mean self-publishing is much more pragmatic than it used to be, people who really want to publish have a means of going outside the conventional system. Some power-law-style stars have already emerged (Amanda Hocking, the 50 Shades of Grey author). Others probably will. Maybe I'll be one. But if I'm not, I don't think I'll be too bothered: I mostly want to write.
Yeah, 99% of self-published books are probably un- or poorly edited dreck, but that 1% count for a lot.
(A side note: I wrote about this a little more at the bottom of this post: http://jseliger.wordpress.com/2012/07/29/links-the-time-for-...).
Namely, that record companies are like VC funds, and the massive cash they make from Def Leppard (or Lady Gaga or whoever) pays for the 1000's of other acts that they fund and then fail.
The returns aren't as dominated by just a few big successes, though. Although I suppose one-hit wonders are a manifestation of something similar: All the returns come from one song out of who knows how many dozens a band or artist may have come up with.