But Amazon Web Services faces increased cloud competition from Microsoft, whose Azure grew 62 percent year-on-year in the fourth quarter
Amazon has moved past the $1 trillion (£760m) mark once again after reporting strong fourth-quarter earnings.
The company first hit $1tn in market value in September 2018, after falling back below the mark.
Amongst large tech companies, only Apple and Microsoft are currently valued in the same range. Apple became the first publicly listed US company to reach a $1tn valuation in August 2018.
Google parent Alphabet surpassed $1tn last month, but has since also slipped back.
Amazon’s share price rose more than 10 percent late last week after it reported earnings for the Chrismas period that substantially surpassed analysts’ expectations.
The company’s net income reached $3.3bn, compared with the $1.97bn analysts had anticipated, while revenues were also higher than expected.
Amazon said an initiative to expand its one-day shipping infrastructure had cost less than the $1.5bn expected.
Meanwhile, memberhship of Amazon Prime, which includes one-day shipping, surged in the fourth quarter to more than 150 million customers, spurred by demand for fast shipping for last-minute Christmas gifts.
Amazon launched its own delivery service after an unexpected surge in 2013 Christmas orders swamped carriers such as UPS and FedEx.
In 2019 the service carried half of Amazon’s worldwide orders, or 3.5 billion orders, compared to FedEx’s 3.8 billion and UPS’ 5.5 billion.
“The number of items delivered to US customers with Prime’s free one-day and same-day delivery more than quadrupled this quarter compared to last year,” said Amazon chief executive Jeff Bezos.
The Amazon Web Services (AWS) cloud service showed sales growth of 34 percent for the quarter, making up two-thirds of Amazon’s overall operating income for the period.
Amazon faces increasing cloud competition from companies including Microsoft, whose Azure also showed strong growth in the fourth quarter.
Microsoft secured a hotly contested $10bn contract with the Pentagon last year, a decision over which Amazon is suing.
Amazon alleges US president Donald Trump interfered in the procurement process due to his personal dislike for Bezos, who also owns the Washington Post, a newspaper critical of Trump.
Azure grew by 62 percent year-on-year in the fourth quarter, and has been expanding its market share by 2 to 3 percentage points each year, according to analysts Synergy Research Group.
Amazon’s cloud market share has been holding steady at around 33 percent, while most cloud providers other than Amazon and Microsoft have been losing share, Synergy said.
Combined AWS and Azure revenues for the fourth quarter grew by nearly $2bn from the third quarter, Synergy said.
The company said Amazon and Microsoft had “(hit) the ball out of the park” with their quarterly cloud figures.
Google is set to report its fourth-quarter cloud revenue figures on Monday.