Cost and requirements. If a website goes offline, what impact does it have? For Amazon, offline equals lost profits. Thus staying online is an imperative. I

Cost and requirements. If a website goes offline, what impact does it have? For Amazon, offline equals lost profits. Thus staying online is an imperative. It is easy to have near 100% uptime on AWS because AWS was designed to support Amazon's requirements. It does cost more because you would need to configure for multiple availability zones and elastic scaling. Is the cost of that increased availability worth it to other web sites? Maybe or maybe not.