From a 2005 New York Times article by Stephen Dubner and Steven Levitt:

“Why would an economist be embarrassed to be seen at the voting booth? Because voting exacts a cost – in time, effort, lost productivity – with no discernible payoff except perhaps some vague sense of having done your ‘civic duty.’ As the economist Patricia Funk wrote in a recent paper, ‘A rational individual should abstain from voting.’ The odds that your vote will actually affect the outcome of a given election are very, very, very slim.” 

Well, the hell with that stuff. Vote anyway. But it is true that voting is not the most effective way to make your voice heard. If only there were some means of freely distributing your political opinion to many people at once in order to influence them…