Negative emotions accelerating users activity in BBC Forum

We present an empirical study of user activity in the BBC Forum and the influence of average emotional content expressed by the user on their inclination to write a post. The users' statistical behavior shows clear tendency to be scale-invariant, which not true for the thread's statistics. The average emotional level of thread decreases logarithmically with the length of discussion - longer thread are more negative. This phenomenon is caused by users that are locally very active and place a larger than average number of negative comments.