An older program called Supercalc, and later Lotus 1-2-3, were "killer apps" - the programs that made the personal computer popular in the early eighties. Many people don't like mathematics, but these programs made it easy to work with or prepare mathematical spreadsheets easily and accurately with only a minimal amount of training. Businesses, and later individuals in homes, rushed to the stores to buy computers.

Those PC computers had an additional advantage. Unlike older products, they had software that could be changed or modified. Your spreadsheet could be upgraded to a newer version, with new and more spiffy and attractive features.

This made them superior to the older computers, that were similar to calculators or cell phones. Those dedicated computers performed a single series of tasks that could not be modified.

These two conditions - the ability to modify the spreadsheet software and the ability to handle complex mathematical calculations with ease - were the basis for the computer revolution.

The spreadsheet was the killer app that brought it on.