1. A system for generating a demographic profile for a set of at least one webpage, the system comprising: a webpage audience information gatherer operative for providing, for at least one webpage, training data including demographic information characterizing an audience of the webpage; and a predictor developing module using a processor to compute at least one content characteristic of said webpage and to develop a prediction process which if applied to said content characteristic would have predicted said training data, wherein the prediction process is constructed and operative to be employed by an audience predicting processor operative, for at least one new webpage whose audience is unknown, to compute at least one content characteristic of the new webpage and to generate predicted demographic information predicted to characterize said unknown audience of said new webpage by applying said prediction process to said new webpage's content characteristic.