This article draws on channel expansion theory to explore the selection and use of communication media by organizational members. Channel expansion theory scholars posit that media richness perceptions are dependent on experiences with communication partners, the message topic, and the communication media utilized. This study tests channel expansion theory in the context of new and traditional communication media. Respondents (N = 269) completed questionnaires regarding their use and perceptions of face-to-face, telephone, e-mail, or instant-messaging interactions. Results indicate that experience with channel, topic, partner, and social influence are all significant predictors of richness perceptions, when controlling for age and media characteristics. Findings also suggest that the richness of a medium is not fixed and may be shaped by interpersonal factors, including one’s relevant experiences.