The much talked about cloud computing market currently consists overwhelmingly of private clouds because of security concerns of large organizations, according to a video recently released by Market Analyst, a value-added distributor of market research.

Although the cloud-based services market is still, generally speaking, in the development stage, big companies such as Wal-Mart are driving the market as early adopters, Susan Esutice, president and CEO of WinterGreen Research, said in the video interview with Market Analyst.

A 690-page study, titled, "Cloud Office and Collaboration Productivity Applications--Markets Reach $21.6 Billion by 2018," is available from Market Analyst. The study, conducted by WinterGreen Research, includes more than 175 tables and figures.

Eustice predicts small- and medium-sized businesses will also migrate to cloud-based services as a way of controlling rapidly increasing IT costs. IBM and, she noted, are market leaders in offering Software-as-a-Service (SaaS), but Eustice predicted that Infrastructure-as-a-Service (IaaS) and Platform-as-a-Service (PaaS) will also evolve as cloud offerings.