We ended up hosting ourselves for a couple reasons: - We found it pretty necessary to control our network end-to-end in order to manage uptime properly, as wel

We ended up hosting ourselves for a couple reasons: - We found it pretty necessary to control our network end-to-end in order to manage uptime properly, as well as protect against attacks. - We see pretty significant economies of scale in terms of purchasing our own machines vs. renting someone else's. Our infrastructure is lean and mean and not super processor-intensive, so we don't have huge spikes up and down (they generally just go up and stay there). - We get to do cool stuff like IP anycasting and datacenter failover, which just wouldn't be possible if we were hosted in the cloud. Long story short, it ends up we had the knowledge and expertise to build our own "cloud" and do so cost-effectively.