I can only speak for myself, but the handling of the Ray Rice attack put me over the top on the NFL. I was able to rationalize the concussion issue ("the players know what they signed up for and are getting well paid for it"), but this on top of everything else is what pushed me to the edge. I'm not going to watch football this weekend, and I'm not sure I'll watch the weekend after that, etc.
And no, I don't boycott a lot of things. Just restaurants that treat me badly, dry cleaners that ruin clothes and don't apologize, things like that.