Amazon has again topped Wall Street expectations, posting revenue up 20 per cent to $US72.4 billion ($99.5 billion), and a record net profit of $US3 billion ($4.13 billion) for the fourth quarter of 2018.

The ecommerce giant’s net income increased 58 per cent, to $US3 billion ($4.1 billion) in the fourth quarter, or $US6.04 ($8.31) per diluted share.

That’s even more impressive considering that the fourth quarter 2017 included a provisional tax benefit for the impact of the US Tax Cuts and Jobs Act of 2017 of approximately $US789 million ($1.08 billion).

Analysts on average expected revenue of $US71.87 billion ($2.54 billion) and EPS (earnings per share) of $US5.67 ($7.80).

It was Amazon’s fifth straight quarter reporting over $US1 billion ($1.37 billion) in profit.

Amazon founder and CEO Jeff Bezos, as he has done previously, touted the company’s Alexa voice assistant, noting that Amazon’s Echo Dot was the No.1 best-seller across all products during the holiday season.

“The number of research scientists working on Alexa has more than doubled in the past year, and the results of the team’s hard work are clear,” Mr Bezos said in prepared remarks, noting that customers spoke to Alexa “tens of billions more times in 2018 compared to 2017.”

Amazon’s Echo Dot is a hands free, voice-controlled device that uses Alexa to play music, read music and connect to home devices. Photo: Twitter

Amazon claimed that during the holiday quarter, “tens of millions of customers” worldwide started free trials or began paid memberships of its Prime program.

But as has been its practice, the company didn’t disclose the count for Prime members; Amazon announced in April 2018 that the company had topped 100 million Prime members globally.

In November, Amazon announced its “HQ2” plans for a second base of operations in North America – after a 14-month public contest in which 200 cities vied to grab the brass ring dangled by the ecommerce giant – would be split between Long Island City in the New York City borough of Queens, and the Crystal City neighbourhood in Arlington just south of Washington DC.

Amazon’s picks generated controversy, as some critics and politicians criticised the nearly $US2.1 billion ($2.89) in tax incentives awarded to the company.

-AAP