  Viral campaigns are crucial methods for word-of-mouth marketing in social
communities. The goal of these campaigns is to encourage people for activity.
The problem of incentivised and non-incentivised campaigns is studied in the
paper. Based on the data collected within the real social networking site both
approaches were compared. The experimental results revealed that a highly
motivated campaign not necessarily provides better results due to overlapping
effect. Additional studies have shown that the behaviour of individual
community members in the campaign based on their service profile can be
predicted but the classification accuracy may be limited.
