Nerdin-out time. Read.
"In health care in the United States, it has been found that 20% of patients use 80% of health care resources.
Several criminology studies have found that 80% of crimes are committed by 20% of criminals.
In the financial services industry, this concept is known as profit risk, where 20% or fewer of a company's customers are generating positive income while 80% or more are costing the company money."
In the blog-posting industry, 80% of content comes from 20% of sources.