The e-commerce measures report the value of goods and services sold online whether over open networks such as the Internet, or over proprietary networks running systems such as Electronic Data Interchange (EDI). E-commerce data were collected in four separate Census Bureau surveys. These surveys used different measures of economic activity such as shipments for manufacturing, sales for wholesale and retail trade, and revenues for service industries. Consequently, measures of total economic and e-commerce activity vary by economic sector, are conceptually and definitionally different, and therefore, are not additive.