About 80 million people didn't vote in the current American presidential elections. While some of these people would have been simply apathetic, a sizeable fraction didn't vote because they saw no point in voting; both the choices were unappealing to them. What if this group, say 20-30 million people, took to casting an invalid vote instead of staying away altogether? People would start noticing this (only about 3% of the total votes cast are 'spoiled' on an average). A better option would be for these people to vote for a third-party candidate, but that would presume that their political leanings were towards one candidate, which may not necessarily be true. This way, they at least present a uniform bloc without splintering their vote.