If you don't boycott, you are indirectly financing an anti-gay organization. Card is a board member of an anti-gay group that actively lobbys and demonstrates against gay marriage. And given Card's past statements about just how much he is against gay marriage, you can be sure he puts his own resources towards that end. If boycotting leads to Card making less money (either by the contract being dropped, or less of a cut for Card), then he will have less money to use to spread hate. And don't get me wrong, I love Ender's Game - my wife and I bought the series a few years ago. And by doing so we unknowingly supported Card's anti-gay agenda. Maybe just a few dollars, or even a few cents of that purchase went to Card. The sad thing is, if I had known about this, and known how good Ender's Game was, I probably would have still bought the book.
That's a classy (nerdy) way to go out! To lend weight to the Battletoads analogy, Terra Tubes is level 9 and this is level 3. As you'll see it is nearly impossible to succeed without knowing what is ahead of you. Normally you would have to fail many times before you learned enough about the upcoming obstacles to get through.