I have a friend who sells her used shoes on EBay. And believe it or not
but they are selling.
As for shoes that are too old to be reused in the US. I give my old
tennis shoes to a former professor of mine who takes them to NEPAL for
his Sherpas and porters he hires for Sierra Club treks.
You may be able to find other international organization that needs
certain shoes. (Note: I heard that one of the big complaints on US
clothing donations to other countries during times of disasters are the
inappropriate shoes - dress shoes and high heals - for the people who
lossed their homes due to mud slides in the rural country side. So we
should be careful not to dump unusable shoes on others._
Ann Schneider