E-commerce giant Amazon (AMZN 0.83%) reported its fourth-quarter and 2021 full-year results on Feb. 3. The response from investors was overwhelmingly positive, sending its stock almost 20% higher in after-hours trading. 

While Amazon is best known for its dominance in e-commerce, the company is now a collection of diverse businesses like cloud computing, advertising, and even electric vehicles (EVs) -- indirectly -- through its 18% stake in Rivian Automotive (RIVN 0.27%). Its investment in the EV maker was responsible for 82% of Amazon's fourth-quarter net income.

Rivian's stock has since fallen dramatically in 2022, so investors shouldn't expect the company's earnings to be carried by the investment forever. But still, Amazon's core businesses are delivering remarkable growth even without it.

A blue Rivian truck sitting outside the factory.

Image source: Rivian Automotive.

Amazon Web Services continues to outperform

Although Amazon's e-commerce business has generated underwhelming operating margins over the past few years, its cloud computing segment, powered by Amazon Web Services (AWS), has done most of the heavy lifting. 

In 2021, AWS accounted for just 13% of the company's total revenue, yet it delivered 74% of its operating income. It's thanks to the segment's operating margin of 29% for the year, which was substantially higher than the e-commerce segment's meager 1.5%. AWS is also outpacing the company's overall growth in revenue, meaning it's becoming a much larger part of Amazon over time.

Metric

2018

2021

CAGR

Total revenue

$232 billion

$469 billion

26%

AWS revenue

$25 billion

$62 billion

34%

AWS revenue as a percentage of total revenue

11%

13%

N/A

Data source: Amazon. CAGR = compound annual growth rate.

Cloud computing as a whole is likely to play a growing role in the corporate world, as the economy continues to shift toward digitization. Amazon Web Services is the largest player in the industry, offering a comprehensive suite of products and services ranging from simple data storage to quantum technologies. Since some estimates suggest the cloud sector will be worth over $1 trillion per year by 2027, AWS still has plenty of room for growth. 

Advertising is a new bright spot

In a surprising move, Amazon announced that it will report its advertising revenue separately from its other segments going forward. On the Amazon website, businesses can pay to place ads in product listings and in search results, and now investors will be able to see just how valuable that digital real estate is.

In the fourth quarter of 2021, the company's advertising business generated $9.7 billion in revenue, which represented 33% year-over-year growth. And for the whole of 2021, it delivered $31 billion. For context, that's more than the $28 billion Alphabet's YouTube video platform brought in last year from advertising. 

Amazon hasn't begun reporting anything other than revenue for its advertising business, so we won't know how profitable it is until it shares more information. But since it's half the size of AWS now, the company will likely draw more focus to the segment in the future.

But Rivian stole the show

Electric vehicle maker Rivian Automotive hit the public markets in November 2021, but Amazon's involvement in the company began well before that. It led a $700 million funding round for Rivian in 2019, in addition to placing an order for 100,000 of the company's electric utility vehicles for its delivery fleet. Amazon views Rivian as an essential part of its plan to convert its entire fleet to run on renewable energy by 2030. 

While Rivian only produced 1,015 vehicles in total during 2021, its stock received incredible support when it hit the market, with investors valuing the company at over $150 billion at its high point. But by the end of 2021, it had fallen from grace along with much of the technology sector, losing 42% of its value.

Still, that was enough for Amazon to record an $11.8 billion pre-tax gain on its holdings. It represented 82% of Amazon's $14.3 billion of total net income for the fourth quarter, crushing even its strong result from AWS. 

Since Rivian stock has lost a further 41% of its value in early 2022, investors shouldn't expect it to make a significant contribution to Amazon's results going forward. But there's no denying the e-commerce giant's incredible group of businesses even without the EV maker, so long-term investors should definitely consider adding Amazon to their portfolios, especially as we learn more about its booming advertising segment.