The article discusses the concept of "online marketing" and particularities of its implementation in infodocumentary institutions. The range of products and services libraries offer is a rich and diverse one. Uninterrupted development and diversification of products/services intended to satisfy user requirements involve efforts to improving communication, learning about new forms of online communication and establishing some clear objectives in informing the community served. Through appropriate promotion, information institutions can create a favorable image, can provoke or amplify the beneficiaries' curiosity for the book and information, for date retrieval tools and systems, as well as interest in studying and information for various curricular activities. The ASEM Scientific Library uses effectively online marketing in social media, focusing on defining the target market segments, and establishes the right tools for organizing and carrying out the activities. The presentation provides examples of tools and methods used to promote products and services of the Scientific Library of ASEM in the online environment. For the effective promotion of the image in the online environment the ASEM Scientific Library, uses its own capabilities through the following tools: website, blog, banners, e-mail, social networks, online training platforms. The creation of library accounts/pages in social networks (Facebook, Twitter, Flickr, Youtube, Google+, Pinterest, Slideshare, etc.) is the most commonly used form of online promotion of the library, which makes it possible to generate traffic, promote the activities and stories of success of the library and, at the same time, attracting new users. The success and image of the library are constituted by its visibility in the community.