The New Yorker has an informative, fascinating and slightly disturbing article on the price war between Amazon, which is selling certain bestseller books for $8.99, and Wal-Mart, which is selling the same titles for... wait for it... $8.98.
Why the penny difference? It's all about market share, and attempting to lure consumers into buying other products once they're at the store or website. But financial expert James Surowiecki explains it much better than I can. Enjoy.