Amazon shares fell in extended trading after it reported earnings per share that came in far below analyst estimates on Thursday.

The company posted third-quarter earnings per share of 52 cents on revenue of $32.71 billion. Analysts expected the online retail giant to post earnings of 78 cents a share on revenue of $32.69 billion, according to a Thomson Reuters consensus estimate.

The stock fell more than 5 percent in extended trading as more than 1.6 million shares changed hands.

The e-commerce giant saw $18.87 billion in North America sales during the quarter. That figure comes in below analyst expectations for $19.09 billion, according to FactSet. International sales, however, came in at $10.61 billion, above Wall Street projections for $10.44 billion, according to FactSet.

In the second half of the year, Amazon has increased its investments in its fulfillment centers and video content, CFO Brian Olsavsky said in a Thursday earnings conference call. He said that this spending is a "step-up" compared to what Amazon did in the first half of the year or the second half of last year.

Amazon's revenue outlook for the holiday season also came in slightly below expectations. The company said it expects fourth-quarter sales between $42 billion and $45.5 billion. The midpoint of that range came in below analyst expectations for fourth-quarter sales around $44.58 billion, according to a Thomson Reuters consensus estimate.

Amazon Web Services, the company's cloud computing business, brought in $3.23 billion in revenue during the quarter. Wall Street projected AWS to bring in $3.17 billion in sales during the quarter, according to a FactSet consensus estimate.