Jim Gray of Microsoft Research has an interesting paper on the economic viability of distributed computing.
“Put the computation near the data. The recurrent theme of this analysis is that “On Demand” computing is only economical for very CPU-intensive (100,000 instructions per byte or a CPU-day per gigabyte of network traffic) applications.”
“If telecom prices drop faster than Moore’s law … [snip] … it could completely alter the arguments here. But there is no obvious sign of that occurring.”