For me the difference tends to be the quality of products. If it's something I have zero interest in buying, I won't buy it no matter what the reasoning. If it's something I like and would want anyway, knowing that the person I'm buying it from needs the money for almost any reason is enough for me to go ahead and buy. I like the idea of helping support someone who needs it, but I'm not going to buy any old crap to do so, basically.