The worldwide public cloud services market is projected to grow 21.4 percent in 2018 to total USD 186.4 billion, up from USD 153.5 billion in 2017, estimates Gartner, Inc. The fastest-growing segment of the market is cloud system infrastructure services (infrastructure as a service or IaaS), which is forecast to grow 35.9 percent in 2018 to reach USD 40.8 billion. The top 10 providers to account for nearly 70 percent of the IaaS market by 2021, up from 50 percent in 2016.
Software as a service (SaaS) remains the largest segment of the cloud market, with revenue expected to grow 22.2 percent to reach USD 73.6 billion in 2018. SaaS is expected to reach 45 percent of total application software spending by 2021. Within the platform as a service (PaaS) category, the fastest-growing segment is database platform as a service (dbPaaS), expected to reach almost USD 10 billion by 2021. Hyperscale cloud providers are increasing the range of services they offer to include dbPaaS.
Although public cloud revenue is growing more strongly than initially forecast, Gartner still expects growth rates to stabilize from 2018 onward, reflecting the increasingly mainstream status and maturity that public cloud services will gain within a wider IT spending mix.