One of the great things about the Amazon book marketplace is that writers have the opportunity to publish their own work. The big publishing companies no longer have the most control over which books are published and while writers can publish their work through vanity presses, they don't have to go to that expense anymore. These days, they can upload their work on amazon, charge $0.99 or $2.99 - almost always for less than $5 - and wait for the readers to find them.
Obviously this - on top of digital books - will revolutionize the publishing industry and I imagine that the main publishers are running a bit scared. The traditional publishing industry doesn't need to give up just yet, however, because they have one thing that many self-publishing writers lack: editors.
Sadly, it seems that many self-publishing authors are unable to spell- or grammar check their works. Many others have no idea how to pluralize a noun, so that something like "the students went to the mall" is often written as "the student's went to the mall". Other common issues include things like their/they're/there, to/two/too, hear/here, and anonymous/anomalous homophones as well as dangling modifiers, comma splices, and inability to keep to one narrative mode.
Sure, these works are cheap, and some say that you get what you pay for so one's expectations should be lower. My expectations are lower with self-published books than books from the main publishers but I still expect basic editing to be completed before the work is published. I've heard that editing costs about $2500 - $3000 per work which would be prohibitively expensive if the author doesn't expect to recoup that cost through sales.
Even so, there must be people out there who are willing to go over the work and edit it without changing the story who are willing to give their help. Maybe authors can help each other by editing each other's works. I don't know what the solution to this issue will be; all I know is that my willingness to take a chance on an unknown author decreases every time I read another self-published book lacking basic editing.
I used to just go ahead and buy the books because they were cheap. Then I read samples of the works, but that's a pain and doesn't always give a true picture. Now I only consider self-published books that have been reviewed: I skim through the reviews first and if I find one that says that the work is in sore need of editing, I bypass it. If there are no such reviews, I download a sample and read that before buying the book. This is a whole lot of work to do for a cheap book, isn't it?
Honestly, sometimes it's just not worth doing, and that's a shame. There are lots of gems hidden in these self-published works but they're easy to overlook because of the sheer volume of badly edited works in the same category. Until these authors realize that good editing is as crucial to the success of their work as the initial idea and story and find a way to get their works edited, self-published works won't be seen and so won't be any kind of threat to the major publishers. The publishing revolution will have to wait.