This paper deals with social media in building experts’ professional images. In the theoretical part, online communities are discussed in the light of the paper’s topic. The study relies on technological adoption models, and in particular, the UTAUT (Unified Theory of Acceptance and Use of Technology) 2 model. In the empirical part, the use of LinkedIn was analyzed as the major tool for professional networking. Our research results suggest that the use of LinkedIn has been initiated mostly by invitation or encouragement of another user. Only in rare occasions, self-branding was reported as the primary motivation to register into LinkedIn. Self-presentation was improved in the process of using the service, as the users became more acquainted with the nature of the service. Experts presented themselves in a minimalistic manner at the beginning. Thus, it would not be accurate to characterize it as strong self-branding. However, they had created personal brands, and they consistently attempted to maintain it. LinkedIn was mainly used to search for professional information and track their friends. The experts could also discuss marketing their own employer company on LinkedIn resulting a shift towards the company's employee advocacy. However, experts wanted to market their employee company only if it is motivating to them and supports their personal expert brand. Our study indicates that, on a practical level, it could be advisable to encourage employees to use LinkedIn actively. However, as a prerequisite, companies should ensure overall job satisfaction, and check that employer/employee relations are fully operational in order to achieve the best possible results of marketing.