Analysis: Leo Kelion, technology news editor, BBC Online
On the conference call one of the analysts expressed surprise at the scale of the margins enjoyed by Amazon Web Services.
The division posted $265m of operating income in the first quarter, which was not only higher than last year's figure, but more importantly not the loss that several analysts had expected.
Even so, Amazon made clear that its business model for AWS was to innovate quickly and then pass cost savings onto customers in order to remain the dominant player.
Recent AWS add-ons include Amazon Machine Learning - a service that automatically analyses clients' data to help them reduce their customer churn and a feature that makes it easier for developers to run "internet of things" apps.
Last year AWS' chief told the BBC that the unit could in time become bigger than Amazon's retail business.
But with Microsoft, Google and IBM among rivals seeking to eat into its market share, the question is whether those margins will hold up over the long term.
More from Leo: Amazon's bid to power the internetnue.