We’re creating a massively-multiplayer social game. We expect up to 1 million concurrent users. The game is not real-time, instead it’s turn-based. We need reliable messaging between our clients and the server, preferably over HTTP protocol.

Besides the multiplayer functionality, we’ll also need a content delivery service.

Could you please recommend a server-side technology for us, so we’ll start searching for the right people to hire?

Is it correct assumption that no single server will hold that amount of load so it must scale horizontally?

Will Windows Azure do the job?

Thanks in advance.