Cloud storage is massive. Very massive. We're routinely encountering new requirements where terms like "gigabyte" and "terabyte" are not useful, the discussion starts at "many petabytes" and goes up from there.
We tend to think of all this stuff sitting in a data center somewhere, but for this model, it just doesn't work. Nobody can afford a single data center that's large enough to put all this stuff into (no, not even Google). More importantly, no one can afford the network pipes that'll be needed in a single place to feed everything into, or out of.
