Did anyone find the site the least bit interesting?
Of course you can't know how many slaves "work for you". It's a hypothetical game to raise awareness (not entirely fiction), with facts and tid bits along the way meant to turn your stomach.
They even state they make huge assumptions, and fail to include the sex question.
The point was to learn about how many things in the world still benefit from forced labour, and that slavery is definitely not gone. In fact it keeps reappearing each century, transmorphed and engaging a new generation of disadvantaged people. So we obviously haven't done a good job abolishing it. That's the point.
You can go one living, shrugging your shoulders about it, saying everything is tainted anyways, or you can think about where your products come from, and care. I'd rather care and be frustrated and angry about it, than live comfortably in a world run in large part on slave labour. Whether the slaves are two states away from me, or two continents away from me, it seems the right thing to do is CARE.