Price comparisons between the providers are not apples-to-apples. CloudSigma, for example, offers a recommended "small" instance size with 1.1GHz of CPU and 1.7GB of memory for $59 a month, according to its quote calculator. Amazon's default "small" instance type with 1.7GB of memory is $0.06 per hour for a Linux VM.
Customers also need to figure out exactly what customized VM size they want or need. Higgins, from CloudSigma, says for many test and development customers, this isn't a problem -- they're technical enough to know what they need and spin it up themselves in CloudSigma's website. Higgins runs a division within the company that works with customers to customize their VMs.
There is also a growing ecosystem of third-party vendors that will help customers optimize their cloud usage. Many of these vendors focus on specific public cloud service providers -- Newvem and Cloudyn, for example, help customers optimize their Amazon resources. But Cloudability is a similar tool that works across more than a dozen providers.
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