, Inc. (AMZN -0.29%) has its hands in everything. 

E-commerce is the company's bread and butter, but the tech giant is also making investments in fulfillment, logistics, and shipping to support core growth, and it's investing in other ecosystem-builders like content, music streaming, and hardware, just to name a few. 

Many of these projects are long-term plays that don't immediately show up in the company's financial results, something a lot of companies couldn't get away with. But a lot of companies don't have a segment like Amazon Web Services (AWS) cutting checks. 

The cloud computing operations sustain Amazon's business and allows it to grow... and one analyst thinks that the company's biggest breadwinner is about to get a whole lot bigger.

Cloud icons over a blurred background

Amazon's cloud computing business could triple. Image source: Getty Images.

A huge and growing market...

Cloud computing gives businesses the ability to access on-demand computing resources, computer programs, and data anywhere an internet connection is available. Accessing and storing these resources on the servers of others, or "in the cloud" on a pay-as-you-go basis can be less expensive than purchasing fixed assets like additional servers, particularly for smaller businesses. 

Worldwide public cloud services revenue hit an estimated $260 billion last year, and is forecast to exceed $411 billion by 2020, according to market research company Gartner.

For its part, AWS generated net sales of $17.5 billion in 2017, up 43% year over year, while operating income grew 39% to $4.3 billion. What was once a sideline has grown to 10% of Amazon's net sales last year, and all of its operating income. The size of the market shows that the company still has a significant untapped opportunity.

... that Amazon will continue to dominate

Jefferies & Company analyst Brent Thill thinks that's just the tip of the iceberg. After attending Amazon's AWS Summit, he believes the company's cloud segment will more than triple over the next five years to $60 billion, saying that AWS "has become the gold standard for millions of customers" when it comes to cloud computing.

Thill cited a number of examples of large-scale migrations of data to AWS:

The vast majority of companies we talk to are building on AWS in a big way -- and today the company announced Shutterfly will be moving its 75+ PB [petabyte] image library to AWS and Cox Automotive will be closing 40+ data centers as part of its transition onto AWS. Last week, GoDaddy also announced its partnership with AWS in which the company will begin a multi-year transition onto AWS, while also bringing GDDY [GoDaddy] solutions (domains, GoCentral, ManagedWP) into the AWS marketplace.

Other opportunities exist

Amazon is the leader in the infrastructure-as-a-service (IaaS) area of cloud computing, in which companies rent space and time on servers, using the pay-as-you-go model. While this segment is expected to see the most extensive growth over the next five years, Thill sees other opportunities for AWS as well. He believes Amazon could move "up the stack" and make a push into the software-as-a-service (SaaS) segment, which represents an additional $100 billion opportunity -- particularly in the area of security, which "remains top of mind for all parties."

The analyst pointed out that "AWS remains the runaway leader in a vast, and still rapidly growing, cloud infrastructure market by a wide margin."

Fund ongoing growth

The juicy operating margin of 25% produced by AWS helps Amazon fund growth in other areas of its business, like the ongoing international expansion of its e-commerce business. While online sales totaled $160 billion last year, they also generated $225 million in operating losses.

If this analyst is right, Amazon will be able to fund a whole lot of growth over the next several years -- and investors will be the ultimate beneficiaries.