It seems that Amazon, over in the USA, has decided that in future any POD (Print on demand) book it sells must be printed by its own company. On top of this, it also demands a very substantial discount from the publisher. This is certainly going to put the squeeze on small publishers and by extension, since a great deal of historical fiction is published by such outfits, is likely to reduce the number of historical fiction books coming on to the market. I suspect it may also have an impact on short-run academic works.
I am going to resist the temptation to rant on the subject, but there is definite cause for concern. You may care to check out some of the following links for more detail.
Amazon's Official Letter
If this development concerns you, please tell anyone you know who is interested in books. Tell Amazon as well!