A growing number of companies are recognising the benefits of using social media in customer relationship management. At the same time, the consumers’ expectations are rising: short response times, individual communication, real interaction with humans, and participation. It is a challenge to observe the many different user activities on many different social media sites. The aim is to reduce the complexity of integrating multiple social media sites with enterprise systems. Therefore, a conceptualisation of user activities in social media is presented. A user activity is a cross-over of an action invoked on an object and a user who acts in a certain context. The 40 user activity types are compared with actual features of ten social media sites. We find out that a substantial share of them can be integrated technically using the social media site’s Application Programming Interfaces (APIs).