[cont] On second thoughts, "scale" is important, because multi-core: (1). spinning up an instance per request is far slower than local, but the second, third, thousandth is the same speed. At some point, the cloud is faster, because it's multicore. (2). the threshold of "fast enough", which means we needn't actually beat local; (3). and the cloud is cheaper.

I was thinking of "web scale" before.