The use of commercial-off-the-shelf (COTS) software has become more and more important in software development. In COTS-based development, COTS component selection is the most crucial phase. Although some selection processes have been proposed, empirical studies are necessary to assess these processes. We describe an exploratory study by structured interviews of 16 COTS-based development projects in Norwegian IT companies. The results indicate that successful COTS component selection can be implemented without using formal processes, and projects with different contexts may use different selection processes. If members in new project has enough practical experience with actual COTS components, such experience can be the dominant factor in selection. In the case of using a new COTS component in the project, hands-on experimentation is needed as an effective way of evaluating the component.