e-tailer giant Amazon (NASDAQ:AMZN) saw shares blast 6% higher after hours as it posted record fourth quarter profit, boosted by strong holiday sales, growth in the cloud business, and advertising sales in North America.
The numbers blew past analyst estimates, with revenue for the three months at US$50.5bn versus US$59.83bn estimates.
READ: Analysts see strong holiday demand for Amazon ahead of fourth quarter numbers
Net income was US$1.9bn, more than double from the same period last year and the highest figure yet for the firm.
This was boosted by a tax benefit of about $789mln under the new US tax laws.
The results also include the contribution from the Whole Foods grocery store chain, which Amazon bought last year.
Meanwhile, for the year as a whole, profit hit US$3bn compared to US$2.4bn in 2016 on group revenue of US$177.9bn - a rise of 31% on last year.
The quarterly revenue jumped 38% year-on-year, while the North America revenue jumped 42% to US$37 billion, while international sales grew 29% to US$18 billion.
Amazon has been heavily investing in recent quarters, into its warehouse and data centre expansion, which seems to be paying off. It has also added more video content for its Prime Video.
READ: Amazon opens first check-out free grocery store in the US
In a call with analyst, Amazon's finance chief Brian Olsavsky highlighted that the strong performance was also down to the group's growing ad business.
"Advertising was also a key contributor as we're continuing to make the offerings more valuable, both to customers and advertisers alike," he told the call.
"Our strategy is to make the customer experience additive by the ad process," Olsavsky added.
"We want customers to be able to see new brands and have an easier time discovering products that they're looking for. For brands, we think the value proposition is that we can find ways for them, especially emerging brands, to reach new customers."
Amazon's advertising business has long been considered the business to watch because the group holds vast amounts of user's shopping data.
It can thus leverage data to help the sellers target customers that have a higher chance of buying online.
In the fourth quarter, other revenue (which includes ad revenue) grew 62% year-on-year to US$1.7bn.
Amazon shares added 6.27% after hours to stand at US$1,477.10.