I worked at Arthur Andersen when Lotus 1-2-3 came out. It was like crack to accountants. VisiCalc was in use but this took it to a whole new level.

One of my jobs was making bootleg copies so everybody could have a copy, until the NY office was busted and they paid out enough to incentivize them to buy copies as needed.

I consider this period of time to be a watershed moment for humanity: prior to this, a lot of business was run on notions and assumptions. With powerful spreadsheets and macros businesses could play "what if" and turn the whole affair into a profit/loss scenario (including labor, e.g., people) and think of businesses simply as a pile of numbers where they only care about maximizing the bottom line.