While War and Peace is a fictional novel, it posits a factual theory that can be examined on practical, sociological, political, mathematical and philosophical levels. I don't want to scare readers with a wall of text, so I'm just going to jump to its conclusion, and presume the conclusion is true, because It made sense as it was written, and I've read articles elsewhere that back it up. We can argue about it's actual truth later. The theory states that the actions that a single soldier do, heavily affect the outcome of a battle, therefore affect a war, and thus can affect the outcome of history. The actions of the single soldier heavily affect the battle because the battle is an aggregate of single actions. The soldier affects the outcome both in and of his own actions alone, and because of the knock-on effect his actions have on his peers around him. The single soldiers actions can even take an in-theory overwhelmingly advantaged side in a battle, and lose it for the Should-Have-Won side, or win it for the Should-Have-Lost side.
This theory obviously transfers into citizen voting actions, and into consumer power to move the marketplace. it is only a sense of disempowerment that leads individuals to not take advantage of the true leverage that they have to affect outcomes.
This is why I take some time to heavily scrutinise new things I'm purchasing (not repeat purchases) for their balance of environmental, health and ethical qualities like slave labour and "fair trade" qualities. I'm buying a better world, one purchase at a time. And I'm prepared to pay extra for it. Even when I was a severely impoverished student and single disabled pensioner, I was prepared to pay extra to buy the world I want in the future.