See
"Amazon, Wal-Mart battling over book pricing" on CNET.
The hot new book by genius Sarah Palin is only $9 thanks to Wal-Mart and Amazon mutual price reductions, and that's only the beginning of the battle.
Someone in the article said, "if anone's going to be the Wal-Mart of the Internet, it's going to be Wal-Mart," a funny comment.
The book price war affected Kindle prices for the books mentioned.
Yes, the genius remark above was sarcasm...