The debate over what officially can be considered cloud computing will get a little more fierce today with the announcement of a bare metal server option from the SoftLayer unit of IBM (IBM) that can be paid for by the hour.

As an infrastructure-as-a-service (IaaS) offering that can be provisioned in less than 30 minutes, the bare metal servers are single-tenant servers connecting directly to SoftLayer’s private network. The debate this latest move sets off, of course, is whether bare metal servers offered in this manner constitute a form of cloud computing or are merely just another instance of managed hosting.

According to the National Institute of Standards and Technology (NIST), the definition of cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources that can be provisioned rapidly and released with minimal management effort. Technically, a single-tenant server doesn’t meet that definition.

The reason this matters largely comes down to bragging rights. Rivals argue that the IBM cloud is nowhere near as large as IBM claims because the majority of it is based on bare metal servers dedicated to a specific application. As such, they claim IBM is misrepresenting how much presence in the cloud it truly has.

Like it or not, however, most customers seem to have adopted a much broader definition of cloud computing than NIST. It is not at all uncommon for an organization to ask a solution provider about cloud computing services, only to wind up buying an instance of managed hosting. They like the idea of having somebody else manage their infrastructure. But when they realize that the classic definition of cloud computing means actually sharing infrastructure with another entity, suddenly the whole multi-tenant idea is not as appealing. There is, after all, a world of difference between living in an apartment building with “noisy neighbors” and a garden community where not only is there more distance between the houses, the plumbing isn’t shared.

IBM SoftLayer CTO Mark Jones argued that what really matters is being able to bring the best of both cloud computing and managed hosting worlds to the customer. In that context, Jones noted 30,000 IBM customers have already voted with their feet to define what cloud computing means to them.

Billing by the hour, of course, is nothing new for cloud computing environments based on virtual machines and not every organization even wants to be billed by the hour. For many a flat fee for the month provides a more predictable cost model for consuming infrastructure resources.

Billing by the hour for bare metal servers clearly is going to blur the line between the definition of cloud computing and managed hosting even further. Whether that’s a good thing or bad totally depends on how much of a cloud computing purist you really want to be.