1. An electronically implemented method for actively exchanging messages in a group of individuals, comprising: a. accumulating messages from individuals in at least one hub comprising a processor; b. processing with the processor and reorganizing accumulated messages and groups of accumulated messages with similar contents into short representations without or with insignificant information loss for said single messages or said groups; and c. selectively distributing, by the processor, messages containing the short representations in place of accumulated messages according to a distribution pattern achieving a constrained maximum of a goodness function depending on the distribution pattern and parameters describing group members and the messages, wherein the goodness function is defined as a linear function, ƒ(d)=Σ X,DεG(X) PI X (D), subject to a linear constraint of a form Σ X,DεG(X) q X (D)≦r, where X identifies different individuals in the group, G(X) identifies a list of messages to be sent to individual X, D identifies one of the messages in the system, PI X (D) q x (D) are real valued coefficients depending on features of the message D and individual X, r is an acceptability constraint and the sum f(d) is over all individuals X and messages D in G(X) jointly and wherein the coefficient PI X (D) uses a probabilistic model of individuals' responses to messages, PI X (D)=1−Π YεA(D) Π c (1−RC D (c)VI X Y (c)), where PI X (D) is identified with the probability that individual X will respond positively, in a certain sense, to message D, and where Y identifies different individuals in the group, c identifies different categories to which a message can be related, A(D) identifies a list of authors of message D, RC D (c) for all c identifies a set of features, valued between 0 and 1, describing the message D in relation to the set of categories c, and VI X Y (c) for all Y and c is a set of features, valued between 0 and 1, describing the individual X in relation to the set of categories c and message authors Y.
2. The method of claim 1 , wherein said processing and reorganizing of accumulated messages is based on a hierarchical conversation format in which a hierarchy of messages comprises a directional parent-child relationship.