They sell the blood the donated blood on the commodities market. All those volunteers organizing local blood drives and people who give blood are just working for free to further enrich the Red Cross.
They recruit heavily at high schools and when my son turned sixteen he donated blood. He had to give a phone number so he gave them my cell number. I got constant calls for financial donations so I blocked that caller. Had a few months respite until calls began again from Red Cross using a different number; blocked that one, too.
Even though I feel this to be true, it is disconcerting to hear more concrete evidence in your posts...:(