With the increased popularity of online social networks, friends become an available recommendation source for decisions that are made on the Internet, such as online purchases. There is substantial benefit in integrating different recommendation sources into one recommendation system so that more information and indeed more relevant information can be provided to the user. However, there is also the burden on the user of having to cope with the broader scope of and sometimes differing advice provided. This paper focuses on the issue of potential cognitive dissonance between the user?s own preferences, social influencer?s (e.g., friend?s) recommendations, and advice from a recommendation agent (RA). It provides a model of how different recommendation system designs can lead to different magnitudes of dissonance and when. It also discusses the role of the user?s product knowledge on influencing the extent of and reaction with dissonance. This paper contributes to the designing of recommendation systems which can create synergies between different recommendation sources to best assist the user.