It's called the slush pile. Amazon currently estimate they have 1.8 million authors with roughly 3.2 million book titles (see this link). For traditional publishing, the publishing houses were the gate keepers in terms of quality. But for ebooks, there is no gatekeeper. Anyone can publish a book, and they do. This process has been going on for a while now.
At the beginning, readers were more than happy to take a punt on books from the slush pile, however, over time that's changed. Customers will only buy so much garbage before they look for a means of not wasting their hard earned dollars. The way this has worked in Amazon is by reviews, and for a while people could look for good reviews left by other readers, and hope for better quality based on the experiences of others. However, even that process is coming to an end.
There are two problems with the review process. The first one is that many readers are either sick of giving reviews, or couldn't really be bothered to begin with. Hardly a day goes by when I don't see someone complaining on Facebook about being hassled by review requests from Amazon. The other problem will probably be an issue in the future and if there's enough interest in this blog, I might post about that too.
Ordinary readers are less and less inclined to leave reviews. The end result is that fewer and fewer quality books are being recognised. In part, because reviews by family and friends are nearly always positive, you need more than just a few reviews, you need a lot, otherwise there is no form of differentiation. So how do you get those reviews when people are less likely to give them? Well, it appears that there is a growing trend toward paying for them.
An author can spend an awful lot of time on book promotion without making much headway. The internet abounds with methods for improving book sales... 'this and this worked for author X and he's now famous'. The trouble being that when 1.8 million authors all hear of this strategy quite a few of them try to use it. The method then quickly becomes overused so it has no further advantage, or perhaps the advantage is significantly reduced. Free book giveaways are an example of this. Time was you could promote a good book by giving away some copies hoping for reviews. This still works to an extent, but nowhere near as well as it once did. Amazon now actually categorize and rank free books separately, there are so many of them. I was quite pleased to have given away around 60 books during one weekend promotion, but this only got me one review. Time was I could have hoped for a couple of dozen.
As things become harder, authors become more frustrated and seek other means of succeeding. I note that in their Feb. 2016 Author's Earning Report, Amazon staff seemed somewhat puzzled by the fact that there were around 500,000 fewer books since their 2015 report. It's pretty clear to me that it was just author's giving up on Amazon. So what else can they do? Already the snake oil salesmen, and some legitimate vendors, are lining up to sell 'the' marketing solution for authors. From videos, to paid reviews, to professional editing, professional book covers, to advertising. Pay, pay, pay. It's already started. It could well be the biggest growth market within publishing... the author market.
"Welcome to the slush pile we'll help lift you out. Send us your first born, your right arm, and your credit card details."
Now all I have to do is work out how to tap into this new market... he thinks cynically to himself.