One method of data collection that has rarely been applied online is the one-on-one interview. Because of its widespread use, the Internet-based service instant messaging (IM) seems to be suitable to conduct scientific online interviews. A unique benefit of IM is the existence of public address books. These can be used both as a sampling frame and as a cross-reference to validate respondents' demographic data. The feasibility of IM interviews was examined in a WWW survey as well as in actual IM interviews that were combined with an experimental manipulation of the request for participation. On the basis of self-reports, respondent behavior, and data in the address books, the studies have demonstrated that the risk of receiving false data in IM interviews is small. Not only is the quality of the obtainable data satisfying but the contact rate, response rate, and retention rate as well. Moreover, the experimental test demonstrated that the response rate is influenced by the information provided in the chat request. On the basis of the study results, recommendations are given as to when and how IM interviews should be used as a data collection method.