In this study we analysed 25 social media tools that have a significant penetration in the market, and defined a comprehensive list of features related to social media technologies. Using a grounded approach, we conducted a cluster analyses to organize tools and their features into categories. Groups of tools that share similar capabilities emerged from the data. Finally, we identified similarities in features among tools in the same cluster. The result is a feature-based classification of the social media tools that are available in the market. The paper proposes a set of research questions intended to guide future studies related to social media features within the organization.