Amazon has reported a net loss of $57m, or $0.12 per diluted share, in the first quarter, compared to a net income of $108m, or $0.23 per diluted share, for the same period in 2014.
Net sales increased 15% to $22.72bn, compared to $19.74bn last year. Operating income also increased to $255m from $146m.
The company reported results for its cloud-computing business Amazon Web Services for the first time. It posted a profit of $265m on revenues of $1.56bn.
Amazon founder and CEO Jeff Bezos said: "Amazon Web Services is a $5bn business and still growing fast — in fact it’s accelerating.
"We strive to focus relentlessly on the customer, innovate rapidly, and drive operational excellence."
The company expects its second quarter net sales to be in the range of $20.6bn and $22.8bn, or to increase between 7% and 18%.
Operating income is anticipated to decline between a loss of $500m and a gain of $50m, compared to a $15m loss reported in 2014.