Mockingbird - Game of Thrones S4 Episode 7 Reaction

Blood plasma is not used commercially. It is given to trauma/shock patients, burn patients, people with severe liver disease, and for many blood clotting deficiencies. People that donate plasma can donate more often, than people donating plasma with blood.

In the US, you donate your blood, but you sell your plasma. When you sell plasma, they give you the blood back. They sell it because it is used in commercial products. Also, I subscribed directly through this site, not Patreon, not sure if it matters...