We started with 1 RackSpace Cloud Server, their most powerful offering, for our development. Our thinking was we'd use cloud servers to scale. Well, RackSpace's top of the line cloud server is, for our application's needs, a total dog. Getting reasonable performance required a server 8 times more powerful than RackSpace offers. And at the rate RackSpace charges for their top of the line dog, we can buy the server we need in 3 months. So, at launch we had 2 servers: one for DEV, one for LIVE; each being 32gigs RAM, 32 cores, & 1.5T disk. Now, 1 year later we've expanded to 6 servers in a half rack with hardware firewall, fully raided up fileShare and passable redundancy.