San Francisco, Calif. — Amazon’s earnings and revenue have jumped 51 percent despite reporting an 8 percent decline Tuesday in earnings for second quarter 2011.

The Kindle maker reported their sales climbing to $9.91 billion, compared to the same period last year when sales were roughly $6.57, surpassing Wall Street’s projected $9.38 billion.

Even while exceeding analysts’ expectation, Amazon’s net  profit dropped 8 percent to $191 million compared to $207 million for this time period last year.  Although the company’s profits fell, The New York Times reported Amazon saying that the profits were sacrificed for a good cause and a stronger future.

Amazon reported that operating expenses were up 54 percent due to the increased advertising for the successful Kindle e-reader, investments in online entertainment and expenditures on new distribution centers.

“Clearly, they have to build the capacity to handle all of this growth. Otherwise, they would have more orders than they could handle,” said analyst Colin Sebastian of Robert W. Baird, who also noted that the April to June quarter showed “accelerating revenue.”

The company recently launched the 3G Kindle, which has become Amazon’s top-selling e-reader device.

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