Amazon got a visit from Santa

Amazon.com Inc. (NASDAQ:AMZN) got some help from Santa Claus this year.

Fourth quarter net income was $98 million in the fourth quarter, or 23 cents per share, compared with $199 million, or 47 cents, because of an increase in income tax expenses. Revenue rose 34 percent to $3.99 billion, the Seattle-based company said in a statement.

Analysts had expected earnings of 21 cents on sales of $3.77 billion, according to Thomson Financial. Sales rose in after-hours trading. It also gave bullish guidance.

The company said first quarter sales will be between $2.85 billion to $3 billion, below the $3.77 billion analysts had anticipated. Revenue for the year will be $13 billion to $13.7 billion, above the $10.5 billion forecast by Wall Street.

Amazon's results were surprising considering the poor performance at Barnes & Noble Inc. (NYSE:BKS) and Borders Group Inc. (NYSE:BGP). The company credited Amazon Prime, a program which allows customers to get free two-day shipping for a yearly fee of $75, for helping to drive sales.

Bloomberg News reported that U.S. holiday shoppers spent more money online at Seattle-based Amazon than other retailers, citing data from comScore Networks.

Still, this stock makes investors uneasy. The company has spent lots of money on new initiatives such as Amazon Unbox, an online video download service. Plus, the company has some pretty tough competitors for price-conscious consumers.

That had an impact in the quarter as the company offered deals to help move more digital equipment and popular toys. Gross margins -- always a worry for analysts -- fell to 21.3 percent from 24 percent a year earlier.

Also check out some other earnings reports that we're following, and let us know what you're expecting.