You have probably observed that often the majority of output stem from the minority of input. It could happen in your business when the majority of sales come from a little subset of your products. Often this ratio is around, but not limited to 20% and 80%.That’s why it’s called the 80/20 rule or principle. Aka the Pareto principle, the law of the vital few, or the principle of factor sparsity.The ratio could be more dramatically like 99.9/0.01 or less drastic 60/40, but the point is that, in most cases, there is a non-linear relationship between input and output, effort, and results.