Growth in Amazon's U.S. Books Business Gets a Second Look

Amazon.com (AMZN Quote) is back under the microscope.

Only two weeks ago, the online retailer made its critics eat crow with a first-ever quarterly profit. The fourth quarter's milestone triumph was only sweetened by a solid rebound in Amazon's closely watched core U.S. books, music and videos business, which had stumbled badly in the third quarter.

But now some people on Wall Street are asking just how Seattle-based Amazon was able to revive the books-music-video business so quickly during an economic slowdown. Judging by regulatory filings and earnings reports, it appears that books-music-video numbers may have benefited from a shift in which Amazon reports revenue from its partnership with Borders.com, the online retail site for Borders (BGP Quote) now co-branded with Amazon.com. Moreover, it appears that many analysts and investors weren't aware of the change. ...