Increased spending on new products like Kindle Fire is cutting Amazon’s profit margin. The world’s largest Internet retailer reported a plunge in third-quarter profit after it ramped up spending on new products such as the Kindle Fire tablet. The shares tumbled 19 percent in late trading on Tuesday.

The Internet retailer’s financial report indicates that the company’s net income fell 73 percent to $63 million, or 14 cents a share, from $231 million, or 51 cents in 2010. According to Bloomberg, Amazon missed the 24 cents predicted by analysts. Amazon also said it may post an operating loss this quarter, as per Bloomberg’s report.

As per this report, Amazon is sacrificing profit margins in search of sales volume and market-share gains. Also, it is selling its Kindle Fire tablet for as low as $199, almost less than half the price of Apple’s cheapest iPad. Amazon’s CEO Jeff Bezos is counting on revenue from digital music, books and movies to make up for selling the product at a loss, wrote Bloomberg reporter Danielle Kucera.

The report quoted Robert W. Baird & Co analyst Colin Sebastian, as saying, “They missed investors’ expectations… The companies’ growth plans aren’t doing enough to spur profit, rather than just sales,” he added. “If they don’t show a corresponding increase in earnings, investors start to scratch their heads,” continued Sebastian.

The company said that fourth-quarter operating results may range from a loss of $200 million to a profit of $250 million. However, as per Bloomberg’s report, analysts were projecting a gain of $512.7 million. While Amazon is expecting sales to be around $16.5 billion to $18.7 billion.

Analysts have indicated that the internet retailer is also losing money due to shipping expenses. Under a prime program, Amazon has been offering unlimited two-day shipping for $79 a year. Consequently, shipping fees generated were only $360 million in the third quarter, substantially lower than the actual $918 million in shipping expenses.