According to the latest report from by International Data Corporation (IDC), the revenue of the U.S. public IT cloud services is expected to experience a compound annual growth rate (CAGR) of 18.5 percent over the forecast period, from $18.5 billion in 2011 to $43.2 billion in 2016.

The new report, titled the U.S. Public IT Cloud Service by Industry Sector, was focused mainly on the public cloud services that are shared among unrelated enterprises and consumers, open to a largely unrestricted universe of potential users and designed for a market, not a single enterprise.

According to the IDC, the forecast is segmented by five functional technology categories and by six vertical sectors. The five functional primary market cloud services segments include Applications as a service, System infrastructure software as a service (SaaS), Platform as a service (PaaS), Server as a service and Basic storage as a service.

On the other hand, the six vertical sectors include:

·         Financial services (banking, insurance, and securities and investment services)

·         Manufacturing and resources (process and discrete manufacturing, construction, and natural resources)

·         Services and distribution (retail, wholesale, professional services, consumer and recreational services, and transportation)

·         Infrastructure services (communications and media, and utilities)

·         Public sector (government, education and healthcare)

·         Home business and consumer

"According to our research, the three verticals that accounted for more than 50% of the spending in 2011 are discrete manufacturing, professional services, and process manufacturing. This is not surprising as these industries are typically less risk averse and compliance focused," said Eileen Smith, program manager at IDC's Global Technology and Industry Research Organization.

"Communications and media, education, and construction were found to be the fastest growing verticals. We expect the media portion of the communications and media vertical to continue to be one of the main users of storage on demand to enable continuous service for content-heavy customer offerings,” Smith added.

The report said that services and distribution, the largest sector in the US public IT cloud services, accounted for 30.3 percent of total revenue in 2011. On the other hand, professional services alone accounted for almost 40 percent of the entire category in 2011.

Manufacturing and resources, the second-largest vertical sector, accounted for 24 percent of total public IT cloud services in 2011 while discrete manufacturing alone accounted for 46.7 percent of the entire category in 2011.

According to the report, the fastest-growing sector was Infrastructure with an impressive 19.6 percent five-year CAGR. The sector accounted for 12.3 percent of spending in 2011 and is expected to account for 12.9 percent of spending by 2016.