[2]Customer retention measurement - Dawkins and Reichheld (1990) calculated a company's "customer retention rate". This is simply the percentage of customers at the beginning of the year that are still customers by the end of the year. In accordance with this statistic, an increase in retention rate from 80% to 90% is associated with a doubling of the average life of a customer relationship from 5 to 10 years. This ratio can be used to make comparisons between products, between market segments, and over time.