"We started making too many calls to S3, and almost took down one of their data centers. They throttled us and it took us a while to figure out what was going o

"We started making too many calls to S3, and almost took down one of their data centers. They throttled us and it took us a while to figure out what was going on; for a while our numbers cratered as users could not connect. We had to move completely off of Amazon and host everything ourselves." Isn't this the exact scenario that people use the "cloud" for? Scaling up massively and quickly?