Rapid developments in e-commerce and e-technology have accelerated intra-business and inter-business online transactions during recent years. Following an empirical survey, critical factors influencing a firm’s willingness to use an e-marketplace are identified via a pre-joining, decision to join, and post-joining research structure. The differences between companies participating and not-participating in e-marketplaces are also examined. However, owing to the samples being limited to Taiwanese enterprises, cautious is needed in generalizing the findings of this study to other countries with different cultures or industry structures.