Ah, I was misremembering an aspect - though the requirement is still there that as users join the storage* requirements will increase in the worst case exponentially, it's not inherent to the ideal system, rather it's a byproduct of cacheing requirements. At a certain point there will be enough users that popular content being accessed will overwhelm the instance hosting it - this is somewhat fixed by caching popular videos on other instances, but as the network of instances grows the need for cached resources grows with it. There may be ways to get around this, if so I'm simply not familiar enough with the current state of the software to know what those solutions are.