NEW YORK ( TheStreet) -- Amazon ( AMZN - Get Report) shares are soaring in after-hours trading after the online retailer beat analysts' earnings-per-share estimates by four-fold and said profit margins held steady.

Amazon's margins, investors' biggest worry in the previous reporting period, came in at 1.45%, in line with the fourth quarter's 1.5%.

The Seattle-based Internet giant reported quarterly earnings of 28 cents per share on $13.2 billion in revenue. Revenue rose 34%, thanks in part to strong Kindle Fire sales. Amazon ended the quarter with $5.72 billion in cash and marketable securities.

Analysts polled by Thomson Reuters expected Amazon to report earnings of 7 cents a share on $12.9 billion in revenue. Independent analysts polled by Estimize expected Amazon to book earnings of 11 cents a share on $13.03 billion in revenue.

CEO Jeff Bezos was extremely positive on the quarter, especially with the growth in books exclusive to the Kindle Store.

Amazon provided second-quarter revenue guidance, with the midpoint slightly below Wall Street estimates. Amazon forecast second-quarter revenue between $11.9 billion and $13.3 billion. Operating income will be between a loss of $260 million and a profit of $40 million. Analysts polled by Thomson Reuters had expected $12.82 billion in revenue and 20 cents per share in earnings.

Shares of Amazon finished the regular trading session higher, up 0.8% to close at $195.99. Shares are sharply higher in after-hours trading, up 9.8% to $215.26, according to

Amazon will hold a conference call at 5 p.m. EST to discuss the results.

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-- Written by Chris Ciaccia in New York

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