Amazon reported a strong first quarter late yesterday, and still shares of the company dropped by 6 percent in early morning trading due to worries about Amazon’s projections for the current quarter. First-quarter profit rose 68 percent.  

Total revenues rose to $7.13 billion, which beat the $6.87 billion expected by analysts. Amazon said it expects revenue of $6.1 billion to $6.7 billion. That would be an increase of 31 percent to 44 percent over last year, but it fell short of analysts’ current expectations of $6.43 billion in revenue.

In a Q&A after the company’s earnings call, Tom Szkutak, senior vice president and CFO for Amazon, said the U.S. Kindle Store now has more than 500,000 books, more than 9,000 blogs and more than 175 U.S. and international newspapers and magazines, according to a transcript provided courtesy of Seeking Alpha.

Szkutak said the company’s long-term goal is to “have every book ever published in any language available for customers in under 60 seconds.”

When asked how Amazon.com might have to change its business strategy, as e-commerce migrates more to mobile devices, Szkutak said the changes represent an opportunity for Amazon.

“We are excited about the idea that the world may shift to a place where 3G connected devices are available to browse net and our view is that the more of web connected devices whether be tablets or smartphones, the better that is for our retails business,” he said.

As of 9:30 a.m. CT, shares of Amazon had gained back some lost ground. Amazon stock was trading at $143 per share.