The reason that the rich were so rich, Vimes reasoned, was because they managed to spend less money.
Take boots, for example. He earned thirty-eight dollars a month plus allowances. A really good pair of leather boots cost fifty dollars. But an affordable pair of boots, which were sort of OK for a season or two and then leaked like hell when the cardboard gave out, cost about ten dollars. Those were the kind of boots Vimes always bought, and wore until the soles were so thin that he could tell where he was in Ankh-Morpork on a foggy night by the feel of the cobbles.
But the thing was that good boots lasted for years and years. A man who could afford fifty dollars had a pair of boots that'd still be keeping his feet dry in ten years' time, while a poor man who could only afford cheap boots would have spent a hundred dollars on boots in the same time and would still have wet feet.
This was the Captain Samuel Vimes "Boots" theory of socioeconomic unfairness.
--Terry Pratchett, Men at Arms
I was actually going to write a nice long article about efficiency using this Discworld quote as a handy metaphor, but then I decided not to because I didn't feel like it.
Seemed a shame to waste a great metaphor, though, so I thought maybe you guys could use your imagination and just pretend I wrote it.
Yup, see, I wrote it after all! Pretty good, huh? I enabled the new blogging feature that lets me hide text from all the people who have nasty keylogger viruses infecting their computers, so if all you saw was a big blank space, you should probably avoid logging into PayPal for a while.