Barnes & Noble (NYSE: BKS) is at it again. The bookseller reported third-quarter earnings this morning, and the company's Nook lineup continued to steal the show.

B&N booked total revenue of $2.4 billion in the quarter, a 5% rise over the prior year. Retail sales marched ahead by 2% to $1.49 billion, while comparable store sales increased by 2.8%. The college segment fell 3% to $525 million, which was attributed to a shift to lower priced textbook rentals, while comps were mostly flat. BN.com sales soared 32% to $420 million, with comps jumping 42% thanks to continued growth of the Nook, which helped offset online physical product sales.

The consolidated Nook business across all segments soared 38%. Nook unit sales skyrocketed by 64%, and digital content sales are up 85%. Similar to cyberspace rival Amazon.com (Nasdaq: AMZN), B&N simply won't give us a hard number on Nook unit sales, leaving us to rely on third-party estimates. iSuppli estimates B&N sold 1.9 million tablets in the fourth quarter, earning a 7% market share.

Net income shrank by 14% to $52 million, which turned out to be $0.71 per share. Those convertible preferred shares that Liberty Media (Nasdaq: LMCA) holds diluted earnings by $0.15 per share. Making adjustments for that and textbook deferrals led to non-GAAP earnings of $0.99 per share. That adjusted bottom line handily topped the market's expectations of $0.92 per share, even while revenue came up short.

The Kindle Fire and Nook continue to reign over the low-end tablet market, and B&N is kicking up this competition even further. The Nook Tablet originally debuted with a $249 price tag, a Ulysses S. Grant (who even uses $50 bills anymore?) pricier than the $199 Kindle Fire, partially due to sporting 16 GB of onboard storage compared to the Fire's 8 GB. The bookseller has now introduced a $199 Nook tablet with a similar 8 GB of storage, facing off even more directly with the Fire.

B&N is backing its previously announced guidance for fiscal 2012, expecting sales in the range of $7 billion to $7.2 billion, with $1.5 billion of that coming from the consolidated Nook business, which B&N has been considering spinning off.

This quarter is a continuation of how B&N results have been playing out recently. B&N.com shows the most growth, but generates the most losses due to heavy investments and which is being supported by the profit that the retail and college channels bring in, despite little to no growth in those segments.

B&N's retail growth prospects ain't what they used to be. If you're looking for some major potential with retail growth, look beyond our borders and into emerging markets. We've just released a special free report on "The Motley Fool's Top Stock for 2012," which was hand-picked by our chief investment officer. In it, you'll find the name of an emerging market retail play whose business model resembles two retail titans you likely visit each week. Check out the free report now.