Nothing you do matters. I know you don't want to hear that because we love this idea of "well, anyone can change the world!" But in your day-to-day life, nothing you do matters.
And I understand that it's fun to pretend we can shut down Wal-Mart by not shopping there, but some people actually seem to believe that. Here's how it works, folks: If you have strong enough beliefs the ABSOLUTE BEST you can do is to live your life according to them. War, Wal-Mart, racism, and patriarchy have been here a long time, and they aren't going away. AND YES I KNOW THAT SUCKS SO SHUT UP. And wanting to get rid of those things is a fine impulse, but I really wish people would realize that, in the grand scheme of things, NOTHING THEY DO MATTERS. I can protest the construction of a new Wal-Mart with my pretty signs and catchy chants, and as a means of expression that's great, but it doesn't actually do anything. And when the store opens I can refuse to shop there, thus keeping my money out of Wal-Mart's hands. That's fine. But to think that anything I do, whether it's protests or boycotts or whatever is so much as a blip on their radar is audacious, egotistical, and insane. They will continue to see revenue that I can't begin to imagine and I'll just have to learn to deal with it.
I mean, I'm trying not to come off as anti-activism, but when you look at what little practical change is actually achieved by activism, you realize that it's really just masturbation. HEY I CAN CHANGE THE WORLD BECAUSE I'M MORE IMPORTANT THAN PEOPLE WHO OMG DON'T CARE!!! I WENT TO COLLEGE AND NOW I KNOW EVERYTHING BUT I DON'T VOTE (even though, short of running for office, that's the only thing I can do that might actually make a difference) BECAUSE ALL POLITICIANS ARE EVIL CAPITALISTIC SCUMBAGS! And granted, I'm just as cynical about politicians as the next person, but they're what we've got and short of violent revolution, which is a stupid idea and will not happen, no matter how much you might like to pretend it will, this isn't changing. Deal with it and get over yourself.
Again, I'm not saying you shouldn't live your life according to what you think is best. If you believe in something, whether it's an idea or a principle or whatever, just live your life accordingly. But don't try and push it on the rest of the world because you will fail and failure is a drag.
tl;dr, activism is a cute idea but if you think what you do as an individual matters in the big picture then you're so full of yourself that I don't want to be your friend.