An applied science called Operations Research was born in WWII. Scientists with a nice pragmatic turn of mind took on the problem of making military operations work better. One famous result was choosing to armour bombers in the places that no returning bombers had damage. They wanted to change the outcomes for those that didn't return.
Second-hand bookshops in Australia generally fill up in the same paradoxic fashion. These are the books that were dispensable, worthless to their owners. The chance of them finding buyers is small. The chance of buying one and feeling happy about it, likewise.
