Konrath recently had this guest post on his blog by an author named Guido Henkel who has self-published a series of old-timey horror novels that aren't selling. He made a bunch of changes...and they still aren't selling. So he's been forced to conclude that the market for this kind of book just isn't there, and he needs to write more-contemporary horror if he wants his books to sell.
And I think that's something important for would-be writers to keep in mind: When it comes to selling books, genre still matters. Probably the two best-selling come-from-nowhere self-published authors these days are Amanda Hocking and H.P. Mallory. Guess what they write? ROMANCE. Romance, of course! Romance, oh, romance, that most commercial of genres! (Fucking romance, if you're me.)
But I still think Henkel is in a better position than he would be had the Jason Dark books simply been rejected and never been published, or had been published by a small press and then not sold. He can move on to another type of book without anyone telling him they won't publish him because his last book sold so poorly. He acknowledges that writing the series made him a better writer, and he's being published in Fangoria now, so his career is definitely moving forward. I think eventually he will hit on something that resonates with readers--and once he develops a fan base, he'll have ten additional books to sell people.