Amazon Posts Profit, Outlook Disappoints  SAN FRANCISCO (Reuters) - Amazon.com Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=AMZN.O target=/stocks/quickinfo/fullquote"&gt;AMZN.O&lt;/A&gt; on  Thursday posted quarterly earnings that more than tripled on  strong international sales but offered an outlook for the  current quarter and next year that was below the more bullish  analyst forecasts, sending its stock down 8 percent.