An Amazon press release said that they sold more Kindle books than paper books. That might be true, but, they probably included the thousands of books being sold for free, or a few dollars. There are numerous public domain books "for sale" on Kindle. I downloaded several dozen.
Here are a few Amazon Kindle tricks.
The web is setting new standards for severely underpaying writers. This blog is a great example: I don't get paid anything at all. There are a number of websites aggressively developing systems that help writers earn as little as 1 cent per word all the way up to 5 cents a word.