The Salvation Army is similarly exploitive. I knew a manager of one of their facilities and had a tour that was (probably unintentionally) eye-opening. For example, he talked about how any clothes they didn't sell in a certain amount of time were sent to their "ragging operation," made into bales, and then shipped to Africa.
The only difference from Goodwill as described here is that the population being exploited are addicts and ex-cons rather than mostly disabled folks. I want to like these organizations, I even think they started out with the right intentions, but greed takes over and ruins them.