The biggest mystery about Amazon's business right now
But Amazon's core has always been, and still is, straight e-commerce.
And although the company impressed investors this quarter by turning a profit, there was one big question that came up several times during the earnings call: What's the story with Amazon's international business?
In 2014, 37% of Amazon's sales come from international markets, but the year-over-year growth rate has been decelerating.
Amazon's North American net sales increased 22%, while its international sales increased only 3% in the third quarter. In all of 2014, North American sales increased 25% while international sales only increased 12%.
"International revenue growth continues to be a mystery and is a confusing part of the Amazon story," analysts at investment firm Stifel write in a post-earnings note.
Stifel made this chart to show how international revenue growth has decreased (emphasis added):
"Could you just help us understand why the international performance is so much weaker?" one analyst asked on Amazon's Q4 earnings call.
CFO Tom Szkutak didn't offer much detail, but noted that Amazon's unit growth rates were better than its revenue growth rates (meaning its selling more goods, they're just not generating as much revenue). He also said the focus on adding infrastructure and fulfillment capacity has affected the operating income, and highlighted India and China as emerging markets that the company is attacking.
"We're very excited about India," he said.
John Rossman, a former Amazon employee and analyst at the consulting firm Alvarez & Marsal, told Business Insider that he wishes the company would elaborate on its strategy.
"Internationally, what are they learning?" Rossman said. "How are they having to adjust relative to local markets? What's working in international and what's not working in international?"
Disclosure: Jeff Bezos is an investor in Business Insider through his personal investment company Bezos Expeditions.