A lot of times these charities are forced to throw stuff out, because it's simply not saleable. There are some people who just cannot throw things out. My grandparents lived through the Great Depression and my grandmother washes plastic silverware and Ziploc bags for reuse - she cannot bear to throw it out. My mother is the same way. She will bring over the most ridiculous things in hopes I can use or fix them. Small scraps of Christmas wrapping paper, half a tube of toothpaste, empty Hallmark envelopes with no matching card... stuff that's not worth the gas she used driving over. Imagine if there were 20 people like her who were donating items like this to charity every month, how much that charity would have to throw out.