How can sustainable online relationships between different parties (e.g. organizations and consumers) be created and developed via computer-mediated communication such as social media and conversational agents? To study my main interest, I take a corporate point of view and focus on message characteristics (language and content use) in online settings. On the one hand, I focus on aspects of monitoring and interpreting online word-of-mouth (WOM) messages. On the other hand I aim to gain more insight into effective (proactive) organizational strategies and language use to initiate online conversations and to distinguish effective (reactive) response strategies to WOM messages (i.e., webcare). Furthere, I explore the possibilities of automated (organizational) messages by means of conversational agents (chatbots) to different target groups in various contexts (i.e., customer service, politics, health and welfare). Data of (large) corpora are combined with experimental studies in order to investigate the effects and related influential factors of linguistic and content elements via these CMC channels.