The internet retailing giant also said it expected to report a bigger-than-expected loss in the next three-month period.
Amazon shares plunged over 10% in after-hours trading in New York.
Investors have long been wondering when Amazon will turn its significant revenues into profits for shareholders.
Amazon has been spending heavily in various new initiatives, including its Amazon Fresh grocery delivery service in the US, and its $1bn acquisition of video game streaming site Twitch.
That has hurt profits at the firm, with operating expenses growing to $21.1bn, compared with the $17.1bn last year.
Investors have been tolerant of Amazon's policy of reinvesting profits back into the firm. But patience has been wearing thin in recent months.
Shares in the firm have fallen nearly 20% since the beginning of this year.
In a statement accompanying its earnings, Amazon founder and chief executive Jeff Bezos chose instead to focus on the firm's holiday offerings during the crucial period in the run-up to Christmas.
"As we get ready for this upcoming holiday season, we are focused on making the customer experience easier and more stress-free than ever," he said.

The rally is being held to mark the 25th anniversary of the creation of the Islamist militant movement, Hamas.
There were also reports of clashes between protesters with Israeli soldiers elsewhere in the West Bank.
On Thursday, a Palestinian teenager was shot dead by an Israeli border guard at a checkpoint in Hebron.
Israeli police said he had attacked a guard and threatened him with what turned out to be a metal toy pistol.
Tensions have been running high in Hebron in the past week following repeated clashes between soldiers and stone-throwing youths.
Hebron is home to about 180,000 Palestinians and some 500 Jewish settlers who live in the centre of the city, guarded by Israeli troops.
On Thursday, the Palestinian Authority allowed Hamas to organise a rally in the West Bank for the first time since 2007. Some 5,000 people took to the streets of Nablus to celebrate the group's anniversary.
Hamas and the rival Fatah faction, which dominates the PA, have made conciliatory gestures towards each other since the end of last month's Israeli offensive on Gaza, which Israel said it launched to stop rocket-fire.
"Hamas steadfastness and victory in Gaza was a big victory for all Palestinian people," Amin Makboul, a Fatah leader, said in a speech at Thursday's rally in Nablus.
A rift developed between the two groups after Hamas won legislative elections in 2006 and came to power in Gaza a year later. Repeated attempts at reconciliation have so far failed.

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Harte's current three-year deal has now expired following the county's 0-18 to 1-11 All-Ireland semi-final defeat by Kerry on Sunday.
However, Harte made clear following the game that he intends to continue on for a 14th year in charge.
"My intentions are to be helping build this team into something even better than they are now," said Harte.
"That would be a very good place to be."
Harte was appointed to the Tyrone job in the autumn of 2002 and has guided the Red Hands to All-Ireland triumphs in 2003, 2005 and 2008.
Earlier this summer, there was some speculation over Harte's future in the role but his team's run to this year's All-Ireland semi-finals appears to have ended any doubts about his position.
The Tyrone boss made no attempt to hide his disappointment after a contest on Sunday that he believed his side could and possibly should have won.
Along with many, Harte felt his team should have been awarded a second penalty shortly after Peter Harte's spot-kick had levelled the game when Padraig McNulty appeared to be bundled over by Aidan O'Mahony.
But Harte accepted that the controversial penalty decision could have been academic if his team had taken a couple of the four glorious goals chances that they created in the contest.
"We didn't take the chances that were presented to us in the way that we ought to have done.
"I thought we were harshly done by for not getting a second penalty and I think a few of those frees, when we got back into the game, after being under the cosh a bit, we needed those scores.
"That would have made a big difference.
"I thought we were as good as them on the day but they have result and that's what will be remembered in history."
Amazon has reported a third-quarter loss of $437m (£273m) - up significantly from the $41m loss it reported for the same period last year.
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About 3,000 Palestinians are marching towards an Israeli checkpoint in Hebron, not far from Jewish settlements in the centre of the West Bank city.
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Mickey Harte has indicated that he plans to remain on as Tyrone football manager in 2016.