"You have a T1 line and have to figure out how many core minutes you can squeeze through that T1 line, which is really an overprovisioning problem," Greaves explains.

Telecom companies also use a unit of measure called an erlang, which describes total traffic volume in one hour, to help determine where they are in the provisioning cycle. "We use exactly the same approach on our cloud," Greaves says. "We can figure out that we're at 1.2, and at 2 we're going to have capacity challenges. So when we hit that 1.2 threshold, that's when we order more hardware."

For Kroll, a cloud storage decision will wait until 2010. "I never like to be on the bleeding edge. [But] I don't mind the leading edge," Kubacki says.

But he adds that cloud storage will still be an attractive option next year. "I think one benefit of moving to the cloud would be the whole concept of it being more of an expense transaction versus a capital transaction," Kubacki. "Today I have a large capital budget; I'm buying my disk and depreciating it over a number of years. So I'm kind of shifting what my P&L looks like by having some of that data in the cloud. I'm not actually buying storage; I'm almost renting it."

Collett is a Computerworld contributing writer. Contact her at stcollett@aol.com.