Do reviews from friends and the crowd affect online consumer posting behaviour differently?

User-generated reviews are valuable resources for consumers to gain information on products which has significant impact on their decision-making. With the development of social network services, consumers are exposed to reviews coming from friends and the crowd. However, the impact of friend and crowd reviews on consumer posting behaviour has not been well differentiated. Using online review information as well as underlying social network information from Yelp, this research develops a multilevel mixed effect probit model to study the impact of consumer characteristics and reviews of different sources. This involves friends or the crowd, and the likelihood of the consumer further engaging in posting behaviour. Despite the common perception that the volume, valence and variance of reviews significantly impact the likelihood of following posting behaviour, we found that such influence comes from friend reviews. The volume of friend reviews had much stronger impact on the target user's posting behaviour than that of the crowd. The valence and variance of the crowd reviews showed no influence when ignoring the friend reviews, but negative influence when considering it. The friend reviews and crowd reviews were further divided for positive and negative valences, and only the positive friend reviews and negative crowd review were found to enhance posting.