This strikes me as another in the long line of "Wow, weird non-white foreigners must be able to do absolutely impossible things!" thinking. c.f. the obsession with Japanese management in the 1980s. We do darn impressive feats of engineering here but they're not magic.
One error in 6 million deliveries? Come on. Has there ever been an attempt to measure the error rate in any sort of statistically rigorous fashion? It should be really bloody simple -- interview 400 customers chosen at random, ask if they've had something not delivered in the last month, last six months, etc. (This will not have nearly enough resolution to detect the difference between 99.999% and 99.9999% accuracy but, ahem, I think we won't quite need to be that exacting.)
[Edit: Other sources cite the error rate as 1 in 16 million. Multiple different numbers which all stand for "arbitrarily small" do not give me confidence in the strength of this urban legend.]
One error in 6 million deliveries? Come on. Has there ever been an attempt to measure the error rate in any sort of statistically rigorous fashion? It should be really bloody simple -- interview 400 customers chosen at random, ask if they've had something not delivered in the last month, last six months, etc. (This will not have nearly enough resolution to detect the difference between 99.999% and 99.9999% accuracy but, ahem, I think we won't quite need to be that exacting.)
[Edit: Other sources cite the error rate as 1 in 16 million. Multiple different numbers which all stand for "arbitrarily small" do not give me confidence in the strength of this urban legend.]