My office investigated using AWS for our application once.

It would require:

* Rewriting the entire code base
* Retooling the entire architecture
* A crapton of security problems since our software is required to be locked behind a VPN (less of an issue for a public MMO, but still something that has to be considered)
* Using a different database (we're in the process of switching now but back then we weren't ready)

We're still looking into it, but the amount of work it would require wasn't worth it for us. And it is a LOT of work.


An MMO, or any program really, has to be built from the ground to work on AWS or Azure. Spinning up extra instances on the fly is already done within the server infrastructure of the current XIV data centers, but it still has a maximum cap (see: Raubhan Ex.)