Social agents have recently been more frequently used in the user interface. However, so far not many studies have been conducted on what impact such interfaces have on users behavior. This paper discusses this and reports on empirical findings, which focus on impact of social agents on user behavior. We talk of social agents as interfaces that act autonomously but are related to the actions of the user. However, to really figure out what social impact these interfaces have on humans, we discuss what characteristics of social agents that should be possible to configure, in order to establish, maintain and develop a fruitful relation with the user. In order to do so, we needed to explore the impact for real users. The exploration of the impact of social agents such as BonzyBuddy the Parrot and Bob, the Paper-clip guy, was done empirically through observations and interviews with users. Based on empirical data collected in the study, a user-agent interaction model was constructed. The m...