Shares in Amazon (NASDAQ:AMZN) shot up more than 18% in after hours trading yesterday, as the company reported an unexpected $92m profit.

Traditionally Amazon has grown its revenue consistently, whilst its profit remained low or non-existant – in the same period last year, Amazon made a loss of $126m. Its announcement yesterday was the first time the company have reported a sizeable profit.

Sales in North America rose 25.5% to $13.8bn in the second quarter, driven by technology and electrical goods. Amazon’s top line grew 20 percent in the quarter, and company profile was boosted by the heavily advertised “Prime Day” on July 15th, where the company gained more new members trying it’s speedy Prime delivery service than ever before.

Founder Jeff Bezos said the results were down to pure hard work: “The teams at Amazon have been working hard for customers,” he said.