CIO — The business benefits of a cloud computing model have been well stated. You cut costs by switching to more flexible on-demand IT resources that can better handle the ebb and flow technology needs at a company.

But adopting a cloud model for your company is a multifaceted decision-making process. Before even sitting down at the negotiating table with a vendor, IT managers and CIOs need to make sure their infrastructures are virtualized and cloud-ready, and that they have a firm grasp of their own security and compliance regulations.

The cloud is also a world with various layers and choices. Do you adopt a public, private or hybrid cloud model? Do you use the cloud for software or your whole infrastructure? Are you a formal (enterprise IT) buyer or an informal (mid-market, SMB) buyer, and how does that affect the model you choose?

CIO — The business benefits of a cloud computing model have been well stated. You cut costs by switching to more flexible on-demand IT resources that can better handle the ebb and flow technology needs at a company.

But adopting a cloud model for your company is a multifaceted decision-making process. Before even sitting down at the negotiating table with a vendor, IT managers and CIOs need to make sure their infrastructures are virtualized and cloud-ready, and that they have a firm grasp of their own security and compliance regulations.

The cloud is also a world with various layers and choices. Do you adopt a public, private or hybrid cloud model? Do you use the cloud for software or your whole infrastructure? Are you a formal (enterprise IT) buyer or an informal (mid-market, SMB) buyer, and how does that affect the model you choose?

Then there are the different service models, aka the "aaS" acronyms: SaaS (software-as-a-service), IaaS (infrastructure-as-a-service) and PaaS (platform-as-a-service).

As these different cloud markets and services splinter off in 2011, business adoption will shift in three significant ways, according to Forrester's 2011 Tech Industry Predictions report.

Public Cloud Uptake Will Be Driven by Informal Buyers

Forrester predicts that in 2011, cloud hype from vendors, the media and other sources will continue to exceed actual user adoption, especially among core enterprise IT hardware buyers (which is what Forrester dubs "formal" buyers).

Adopters of public cloud services will be from the "informal" buyer camp, which are mostly small and midsize businesses or enterprise users who are outside the core IT operations and transaction teams. These buyers are more likely to follow the IaaS and PaaS models and put all their IT resources (servers, storage) in a cloud environment. The Forrester report also predicts that buyers of SaaS applications will continue to be informal business buyers.

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In a survey of enterprise and SMB decision makers conducted by Forrester that asks users about their plans to adopt the IaaS cloud model, 16 percent of "informal" buyers said they have implemented an IaaS model already, and 10 percent said they are planning to implement one in the next year.

Comparatively, 6 percent of "formal" IT buyers in the survey said they have implemented an IaaS model already and 7 percent said they are planning to implement one in the next year.

The IaaS model consists of the pay-for-use hosting of virtual servers by service providers such as Amazon Web Services (AMZN), Terremark, Savvis (SVVS) or Rackspace, to name a few.