Social interaction between participants can lead to increased number of contributions, increased number of participants, and long-term participation. Opportunities for social interaction are especially promising for retaining participants on the long-term participation, and the lack thereof can be a reason for stopping to participate.
More specifically, providing the opportunity for social interaction with more experienced participants is important for recruiting new participants as well as for increasing the number of contributions of new participants. Furthermore, allowing for social interaction with someone who is participating a little bit more, can also lead to increased contributions for those participants that can identify with that person.