1. A method of predicting an increase in sales from a plurality of online public discussions, comprising: receiving a product information input for defining a product for which sales are predicted; receiving a temporally defined input in which the product is discussed; generating a restriction for the temporally defined input; filtering the temporally defined input with the restriction; generating a signal describing the filtered temporally defined input; analyzing the signal to identify at least one characteristic that reflects substantial change in the importance and flow of the temporally defined input; and predicting the increase in sales of the product from the characteristic of the signal.