It means that a huge "middle ground" of opportunity has opened up for novel writers. Just think about the situation before the Internet came along.
At one of the scale, you had the A-List authors – the kings and queens of the publishing industry whose books were stacked high in the stores. These folks made a lot of money from their writing, and rightly so.
At the other end? Those rejected writers who, frankly, didn't deserve to be published.
The huge "middle ground" was occupied by two sorts of novel writers.
Those whose books were rejected – not because the books sucked but because the publishers couldn't see an economic case for investing in them. As the classic rejection slip said, "Great book, but we can't see a market for it." Those writers who were published, but whose books failed to earn back the advance. In short, these writers made a few thousand dollars (max) and then weren't published again. Yes, they had the kudos of being a "published author." But hour for hour, they would have earned far more money flipping burgers in their local fast food joint.
The only escape from this "no man's land" in the middle was self publishing. But like I said, self publishing was a huge financial risk. Plus you had to put up with the "self published = can't get published" jibe.
