Look, when I was a kid, a brand new hardcover cost $15. Then it went up to $20, $25, and now a lot of them are close to $30. The whole time the publishing companies cried cost of publishing increases and inflation.
Now that they are fighting with Amazon, some publishers claim that the printing cost of the book is only 8 - 10%. Wait, why did the cost of books skyrocket if the printing prices didn't really skyrocket? Oh, right, convenient excuse to raise prices and increase profits.
Look, I'm not ignorant. I know publishers pay to advertise (some books) and have other assorted costs. But, I also know how businesses operate. Any excuse to drive that bottom line as high as it can go. Macmillan is skirting the issue that for e-books, they are really just a middle man. So sorry that you can't grab fistfuls of cash for each book sold on Kindle, but you didn't really do much to earn it. Welcome to the future. You can now join the RIAA in trying to extort people since you can't sell them overpriced product like you used to.
And Amazon? They're not completely innocent. Obviously they are in it to make money as well. But, as a consumer, Amazon's $9.99 price point looks a LOT better for a few KB of information than almost the same price as a hardcover. Why would publishers think that you would spend $25 for a Kindle version of a book that costs $27 in a book store? Oh, wait. They don't. They want you to buy the real book, because they make more money from you that way. Sure, Amazon makes more money than the publisher from Kindle book sales. Duh. They marketed it, sold it, sent it to you on a cell signal they pay for, and let you read it on a device they paid to develop and market.
Pulling all Macmillan stock from sale was a pretty douchey move overall, but I get where Amazon is coming from. Hi. We're Amazon. We'd like it to go this way, and if it doesn't, well, we'll see how you like losing sales from the largest online market in the world for a few days. I'm sure that will press home the point. We'll see how it actually works out.