Amazon.com posted solid revenue growth in cloud computing for four consecutive quarters.

This eases concerns that the multi-cloud system could reduce its market share.

Amazon’s robust cloud performance illustrates the continued rapid growth of the cloud industry, particularly for the tech giants.

According to forecasts by Synergy Research Group, total spending on cloud infrastructure services grew by 37% to $178 billion in 2021, surpassing the 34% growth registered in 2020.

The three largest cloud providers, Amazon Web Services, Microsoft Corp’s Azure and Google Cloud, each increased their market share by a percentage point in the last quarter of 2021 compared to the previous quarter.

Canalys forecast a 33% share for AWS, 22% for Azure and 9% for Google.

“Multicloud doesn’t mean spreading your wealth across multiple clouds,” said Sid Nag, vice president at tech advisory firm Gartner. “There’s still a primary cloud you’re doing most of your business with.”

Capital One, which is said to be the first major U.S. bank to fully transition data centers to the cloud and struck an early deal with AWS, is a good example.

While it has used Google and Azure for a few needs, it has become one of its biggest customers with AWS, according to two insiders.

For many tech giants, clouds have become key growth drivers. AWS represented 13% of Amazon’s revenue and 74% of operating profit in 2021. 7.5% of Alphabet’s revenue was in the cloud. 37% of Microsoft’s total revenue was in the Intelligent Cloud unit, of which Azure is a major sector.

Amazon attributed its cloud growth in 2021 to the expansion of its sales team, the expansion of data centers to new regions, and new clients embracing the cloud in the midst of the ongoing pandemic.