If what matters to you is actual electoral support, there's no reason to be voting third party anyway. Both Stein and Johnson got less than 1% of the vote in 2012, and even combined only about 1.2%. The most successful third-party/independent Presidential candidate in decades was Ross Perot in 1992, and even winning just under 19% of the popular vote he failed to win any of the electoral college. It's a self-serving double standard to tell people to pass up the major party candidates but then vote based on electoral support for the third parties, ignoring how well their ideological and policy positions actually align with your own.