[jedsmith]

Reddit didn't start with the cloud, though. Very early, they were on dedicated and found it inflexible to their needs, and scaling a site with the eyeballs that Reddit has would have been very difficult with their first architecture.

The "exit plan" is, really, not marrying your entire architecture to one provider. Spreading the love gives you a bargaining chip and flexibility to see which provider will perform better for you in the long run, and allows you to see the strengths and weaknesses of each. Internet latency is pretty bad, though, so sharding an app across multiple providers can be a bit of a challenge.