The American Customer Satisfaction Index (ACSI) is a national economic indicator of customer satisfaction originally developed in 1994 at the University of Michigan. Each year over 70,000 customers are surveyed about products and services to generate data that is analyzed using an econometric model to benchmark customer satisfaction levels across over 230 companies in 43 industries. The ACSI aims to provide insights into customer satisfaction levels and experiences to better understand relationships between satisfaction and key economic indicators.