Businesses looking to optimize their cost based on their existing deployment, and are certain of their usage levels may decide to purchase either a "spot" or "reserved" compute instance. In a nutshell, the former allows businesses to leverage unused compute capacity for a lower price, while the latter lets businesses pre-book and/or pre-pay in advance for the same. For obvious reasons, spot instances may not always be available in a particular region.
[AWSReservedInstance.jpg. Caption: "You can pre-book capacity up to three years in advance, and pre-pay varying amounts so as to command a better price."]
AWS itself offers a Trusted Advisor service to help tweak various aspect of an AWS deployment, including security and keeping cost optimized. However, a paid support plan is required to unlock all recommendations.
We've only covered the tip of the iceberg in terms of the possibilities available on AWS, but this should point you in the right direction in deciding if you'd like to go with AWS, and to start asking the right questions on how to proceed next.
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