These include strictly regulated financial services companies that are required by law to store client audio conversations and other large data files, and content delivery networks that store and then stream images, audio and video to customers. More and more, users within companies are tapping cloud storage for pilot projects and proof-of-concept initiatives, Ziernick says.

Schumacher Group, an emergency medicine management and staffing company based in Lafayette, La., stores a range of documents, including contracts and reports, on Salesforce.com's cloud platform, Force.com. It also houses all accounts receivable, general ledger and accounts payable data in a hosted PeopleSoft enterprise software system, and its employee benefit information on a hosted system from Workday Inc.

"We have over 50% of our processes living in the cloud currently," says CIO Douglas Menefee. "All are sizable data sets with thousands of transactions being performed on a daily basis," he adds. He anticipates that by the end of this year, 75% of the company's processes will be in the cloud.

Public clouds remove the need for server and storage administrators, but not all technical resource requirements go away, according to ParaScale's Maxey. Many public cloud storage services use newer protocols, such as WebDav or REST, for access, he notes. If a customer's in-house applications don't support those protocols, the technical staff will need to make changes to code. Otherwise, Maxey says, "it's like being dropped in a foreign country and not knowing the language."