The difference between a third party getting 1% of the vote versus 10% could have some impact on politics even if it doesn't affect the outcome of the election.
But just voting to vote is useless. People seem to have the mentality that you pick the lesser of two evils, which is BS. I'm not going to vote for somebody if I don't feel like they are completely up for the job. I'm not going to vote for a 3rd party just so they can get funding because guess what, this years candidate may be great but the funding would be for the next round and who knows who they will have then.
If you're left with the choice between the lesser or two evils on how to run the country. It is very _very_ important that you get the _lesser_ of those two evils.