Similarly, I've long said that the most efficient action you can take(assuming you're not some manner of celebrity) is to vote. Yes, the actual impact of a vote is trivial, even in a close race - "one vote never made a difference" is a trope for a reason. But everything else that an ordinary person can do is statistically trivial too, and voting at least has the virtue of being fast. There's no point in campaigning on an issue and not voting - yes, the absolute change you can cause by campaigning is higher, but the change per unit time is vastly worse. I've known friends who devote great effort to campaigns and then refuse to vote, and it's always just wierded me out.