Because they will be outsourcing a big chunk of that work they do inefficiently (backups, monitoring, provisioning, etc.) to Amazon, which is much better at it.

Because they will be outsourcing a big chunk of that work they do inefficiently (backups, monitoring, provisioning, etc.) to Amazon, which is much better at it. Hence the proliferation of things like hosted AWS Outlook system [1]. Anyone in our Bay Area bubble of efficient IT would say keeping that running for a 2,000-user business is probably... what, a half of a full-time-equivalent of workload, averaged over long periods of time? Less? But Amazon can charge $4/user/month (in this hypothetical company that's round about $100K/year) and it is totally a steal, because a lot of companies will not be able to keep it running it anywhere near that budget. And that is the market they're going for - note that the free trial is 25 users. This is not a product for the small company that just doesn't have the capital to invest in their homegrown solution - that's Google Apps for Work. [1] https://aws.amazon.com/workmail/ https://aws.amazon.com/workmail/