There is an increasing demand for doing business online, which calls for higher business interoperability on business-to-business (B2B) electronic market places (EMp). This drives the development of integration technologies for improving B2B electronic market (EM) functions on EMp. This paper argues that with the development of integration technologies companies will use more private, community and public EMp and select their proper type of EMp when comparing the function–cost ratios of business interoperability on different types of B2B EMp. This argument has been validated through the case studies against a method of historical event analysis. In this shift, four integration factors of standard flexibility, enterprise integration, service provision and semantic integration are constantly improving EMp functions, which lead to an overall reduction of interaction cost for business interoperation on all types of EMp. This will change business behaviour and corporate strategies of most firms, and have important implications for firms to make strategies of how to select EMp to increase business interoperability for higher competitiveness. © 2007 Taylor & Francis Group, LLC.