Amazon reported fourth quarter sales after the close of the market on Thursday, with sales of $25.6 billion (up 20 percent) and net income of $239 million, or 51 cents a share. (That’s a profit margin of less than 1 percent.) Analysts were expecting higher sales and earnings, and the stock is down sharply in early after-hours trading but finished down $19 a share — after gaining about the same amount during regular trading, so a wash on the day. North American media sales in the quarter were $3.5 billion, up 21 percent, and international media sales were up only […]