From Knuth’s book Sorting and Searching:
Computer manufacturers of the 1960’s estimated that more than 25 percent of the running time of their computers was spent on sorting, when all their customers were taken into account. In fact, there were many installations in which the task of sorting was responsible for more than half of the computing time. From these statistics we may conclude that either
- there are many important applications of sorting, or
- many people sort when they shouldn’t, or
- inefficient sorting algorithms have been in common use.
Computing has changed since the 1960’s, but not so much that sorting has gone from being extraordinarily important to unimportant.