Amazon Web Services launched almost 10 years ago. Historically, Amazon has not broken out AWS in it's financial reports. In the absence of hard information, there has been a lot of speculation about how big the business unit is, and whether AWS made any money or not. Especially when they keep cutting prices.
Today, in their quarterly report, they change their reporting and broke out the details for AWS, including a two year historical view. And AWS is a great business: $1.57 billion of revenue and profits of $265 million in Q1 of 2015. For 2014, AWS had $4.64 billion of revenue and $660 million of profit.
That's a nice little business.