E-commerce heavyweight Amazon today disclosed in its quarterly earnings statement that its subsidiary Amazon Web Services (AWS), the biggest public cloud currently available, generated $1.82 billion in revenue in the second quarter of 2015. That means revenue grew by 81 percent year over year — a high growth rate for sure. For the year that ended on June 30, the cloud brought in $5.97 billion.

Operating income for the quarter was $491 million, up 407 percent over last year. Operating expenses for the quarter came out to $1.43 billion, up 54 percent. This marks the second quarter that Amazon has broken out financial figures for AWS. The first time, just three months ago, Amazon revealed that AWS had generated more than $5 billion in annual revenue.

While Amazon has been the leader of the cloud infrastructure market for years, it faces competition from many directions, including Google and Microsoft, but also, more recently, Chinese e-commerce giant Alibaba, with its growing Aliyun cloud.