This article is an excellent corrective to the Amazon bashing that’s been going around lately:
But Amazon is a quintessential capitalist enterprise, and it cannot be faulted for exploiting the free-market system that, for better or worse, we have embraced. It offers people things they want to buy at prices they want to pay, and in so doing, it puts out of business other enterprises that are not able to match its terms. Other than continuing to make sure that Amazon’s practices fall within the bounds of what regulation we have—particularly antitrust laws—there’s not much to be done. (Although it does seem unnecessary to deliberately increase Amazon’s monopoly, as the Wylie Agency did last week with its controversial introduction of a digital publishing venture that makes classic books by the agency’s venerated stable of writers—including Bellow, Nabokov, and Rushdie—available exclusively through Amazon.) I’m not ashamed to admit that I buy books from Amazon when it’s convenient, as well as from Barnes and Noble, independent bookstores, people on the street, or whoever else happens to have what I’m looking for. And to Jeff Bezos and everyone else who brings books to the world I say: thank you.
Eoin Purcell's Blog 
Here’s a fairly worrying report and a fairly good reason not to shop with Amazon:
http://business.timesonline.co.uk/tol/business/industry_sectors/retailing/article5337770.ece
Also, while the author (of the piece in favour of Amazon) does mention Amazon’s tactics with regard to publishers, I don’t think he really goes into much detail (probably because it wouldn’t serve his argument well). Selling books at below cost – and essentially selling second hand books at nothing – devalues people’s sense of worth of a book. Okay, that’s just an opinion, but it translates into fact when people will refuse to pay €20 for a book because they expect to see it drastically reduced.