Vilfredo Pareto's Principle, or The "Pareto Principle," is more commonly known as the 80-20 rule. It suggests that a ratio of approximately 20% to 80% can be found as an effective measure for most things in life. Whether revenues generated per customer or value for hours worked, it usually can be found that 80% of all of our results in business and in life come from only 20% of our efforts!

As importantly, the 80-20 ratio seems to hold true for many input/outputs, causes/consequences, or efforts/results. It also holds true across the spectrum of relationships, business, finances, time