•Is there a clearly defined application for IaaS? It's important to know what this platform will be used for. Data storage, data analysis and application development are just some of the potential uses for IaaS deployments.

•How much does your business want to pay for these services? Pricing across vendors can be confusing as it is difficult to compare like-with-like. Can you use less server processing power to pay for more storage?

•Have you considered the bandwidth that will be needed? The efficient deployment of IaaS will need robust bandwidth. Vendors will pass this cost on to their customers, so check what these costs look like before buying.

•Is your service level agreement (SLA) clearly defined? Uptime is a key component of the SLA, but also look at maintenance and any other costs that may not be immediately apparent.

•Can your vendor's platform scale on the fly? One of the key advantages of using IaaS is the elastic nature of the virtual machines. Look for how easy the platform allows for more server space to be added with auto-scaling features.

•Is Hadoop/MapReduce support important? Performing queries on massive datasets will mean implementing Hadoop. Ask how your vendor handles this and what levels of technical involvement your business will need to gain meaningful results.

•How much storage do you need and of what type? The levels of latency that your business can allow will determine what kind of storage will have to be attached to the IaaS platform. Block storage can get expensive, so check how much is needed and what this will cost before buying.

At the moment Amazon's Web Services reign supreme in this marketplace, but other pretenders to their throne are fast developing their own platforms. Google is a clear contender and HP, IBM, Dell, Verizon and Microsoft cannot be ignored.

From an IT manager's perspective this additional choice gives them many more options than had previously been available.