[dekobon]

Nowadays, you don't need to do that yourself to run a cloud because you have companies like Joyent offering fully managed private clouds at a fraction of the cost of AWS. They will rack and stack, manage the cloud software, provide escape plans so you aren't locked into them as a vendor and provide architectural guidance to your app teams.

DISCLOSURE - I am a Joyent employee.

[godzillabrennus]

Even Facebook leverages colo facilities as some of their POP's. Still, I think it's common that somewhere near the mothership these big guys build a facility from the ground up.

[jauer]

FB uses colo facilities as POPs because that's where the eyeball networks connect. It's strictly a latency/connectivity play.